[Android Q&A, Help & Troubleshooting] jheenan:
First I cannot post clickable links because I do not have enough posts on this forum to allow this.

Sorry the instructions I used to unlock the bootloader were not were on the whirlpool forum. I got them from http://mate7.net/ascend-mate7-bootloader-unlock/

Wherever a product model is required to be used it is sufficient to use 'Huawei Y300-0000' instead of 'Huawei Y550'.

However I did not use any software packages from Huawei. The Y550 works with generic USB drivers provided by Google for use with fastboot and adb. If you only want to use fastboot or adb then then you can get them with drivers from the Android 'SDK Tools Only' link at

http://developer.android.com/sdk/index.html

I will provide further links below and mix them with basic information. I am sorry the basic information parts will appear unnecessary to experienced readers.

You need to remember you can easily end up appearing to brick your phone. In most cases it won't be bricked but if you are not experienced it will appear to be. Also manufacturers won't honour warranties for phones that have had their bootloaders unlocked. For example Motorola forces their users to view extreme warnings after their phone bootloaders are unlocked, refuses to provide further support and refuses further warranty.

Please note unlocking here does not refer to unlocking the phone for use of SIM cards from different carriers.

Your best safeguard is as soon as you have a working recovery image (such as TWRP) installed with fastboot is to use it to back up your boot, data and system partitions to an SD card Although TWRP now uses MTP for file transfer with PC it does not work reliably. So reboot into Android and transfer the backup to PC, if you do not want to remove the SD card. When you have done this you then do not need any software from Huawei to restore or 'unbrick' your phone. If you have no experience with TWRP then it is strongly urged you practice attempting to restore backups you have personally made. You should always use an SD card with the Y550 and use this as the backup location (choose 'External SD' in TWRP as the backup location). Warning: a restore will wipe your system partition and wiping your system partition means you cannot even do a 'a factory reset' type recovery if the restoration fails due to an incorrect backup. Of course you can ask Huaweii for help or look for images on the net to load with TWRP or fastboot. Huawei has no obligation to help, level 3 support will not understand your problem and you have near zero chance of finding the correct image easily or even at all on the Internet. So the lesson is backup and test restoring your backups. Triple check you are backing up boot, data and system partitions and check the contents of backup directories before restoring. Use the MD5 files to check backup integrity. If necessary ask a friend for help or a demo. There are no excuses for failing to take a proper backup. No one will sympathise with your plight and you will get labelled an idiot if you did not take a backup and you need to restore from backup.

The first task is to unlock the bootloader. You need fastboot to unlock the bootloader and the Y550 need to be in locked bootloader mode to use fastboot for unlocking. To put the Y550 into bootloader mode for fastboot use without the oft repeated complicated procedure of enabling developer mode in Android followed by 'add reboot bootloader' then

power off the the Y550

keep vol down pushed down

press power button and release both buttons when phone vibrates

Once in bootloader mode, if the Y550 is locked it will say in red at the bottom 'PHONE Locked'. If it is unlocked it will say instead 'PHONE Locked'. You can only use fastboot for limited operations if the bootloader is locked. To power off or reboot from bootloader without fastboot then the only way I know is to remove the battery.

Bootloader unlock instructions are available from http://mate7.net/ascend-mate7-bootloader-unlock/

Wherever a product model is required to be used it is sufficient to use 'Huawei Y300-0000' instead of 'Huawei Y550'.

Warning: unlocking the bootloader wipes data and cache partitions. This forces the phone into a factory reset on next boot if you do nothing else. So backup important data first.

Assuming you have accepted the risks and unlocked the Y550 the next task is to load a recovery image into the recovery partition. I used TWRP 2.8.4.1 in file TWRP_y550_02150131.img from https://drive.google.com/file/d/0B5KRmU8P96dleDVJclJ4NXpzbWs/view

The link is from the last post on http://xdaforums.com/android/help/to-root-huawei-y500-t2923318/page15

Test the image first with

fastboot boot TWRP_y550_02150131.img

if no problems then install TWRP with

fastboot flash recovery TWRP_y550_02150131.img

To boot into the TWRP on the recovery partition quickly without the complicated procedure of 'adb reboot recovery' with phone in developer mode.

power off the the Y550

keep vol up pushed down

press power button and release both buttons when phone vibrates

By the way there is no need to install SuperSU if using CM (CyanogenMod) as CM as its own root access software.

Assuming you have practiced and are now comfortable using TWRP the next task is to load CM11 and gapps (if required) for the Y550. This is the simplest part.

For CM11 I used Patrik.KT's build, cm-11-20150131-UNOFFICIAL-c8817d.zip, available from

https://drive.google.com/file/d/0B5KRmU8P96dlbzloMzY5UGpIaE0/view

The link is from second post at

http://xdaforums.com/android/help/to-root-huawei-y500-t2923318/page17

For gapps I used the then latest 'Google Stock Package', pa_gapps-stock-4.4.4-20150208-signed.zip, available from a link at

http://xdaforums.com/showthread.php?t=2397942

Just copy cm-11-20150131-UNOFFICIAL-c8817d.zip and pa_gapps-stock-4.4.4-2015XXXX-signed.zip onto the SD card of the phone, reboot into recovery and use install in TWRP.

If further clarity is needed then please ask.

That is it. Good luck. No Huawei software that was not already on the phone was used. No firmware partitions touched.

Some very minor points:

Strictly speaking you do not need TWRP or another working recovery image as fastboot on the PC will do the job instead with phone in bootloader mode linked by USB to the PC. While TWRP looks daunting at first, it makes everything a lot easier.

TWRP for the Y550 does not read the date correctly when appending date to backup name. You can manually assign a backup name to correct for this.

The gapps stock install removes the CM11 messaging and browser apps. This means the CM11 lock screen need to have two of its lock screen 'swipe to' buttons edited. These 'swipe to' buttons do not appear on the CM12 lock screen.

The compass does not work in 'GSP Status and Toolbox'. But it does not work wither in CM12 on the ZTE Open C. It may be a software issue as other software is able to read the compass sensor sucessfully.

John Heenan