[Android Q&A, Help & Troubleshooting] GuestK00243:
Use a CM Rom for your Base as these are tried and tested (you can use Stock also as long as you are porting to another similar Stock Rom hardware)

(Make a backup copy of all the files your download - you may need to extract the files again later)

: : : You will not need to re-sign your rom.zip as you will be using an existing already signed rom : : :

: : : The drag and drop method does not require you to re-sign the rom : : :

: : : You will need notepad++ (win) or TextWrangler (mac) to edit build.prop files and scripts : : :

: : : You will also need winzip7 / winRAR (win) or Springy / B1FreeArchiver (mac) to edit the rom.zip files : : :

Find your a working Base Rom for your mobile and extract the contents to your desktop, then delete the following folders from the desktop

system/app

system/fonts

system/framework

system/media

system/priv-app

Edit the build.prop file in the Base Rom >system folder to reflect your new Port Rom details - these vary depending on the port your are using

The lines you need to look for are as follows;

ro.build.id=

ro.build.display.id=

ro.build.date=

ro.modversion=

Now find the Port Rom you want to go to making sure it is close to your manufacture as possible [for example; xperia SP use xperia Z - these have similar screen sizes and hardware]

Extract the contents as before and now copy the following folders back into the Base Rom on your desktop

system/app

system/fonts

system/framework

system/media

system/priv-app

Now open the original Base Rom .zip (do not extract it) with winzip7 or winRAR and delete the following folders

system/app

system/fonts

system/framework

system/media

system/priv-app

Now with the .zip still open 'drag and drop' ALL the folders from your desktop Base Rom into the now open base Rom .zip over-writting any existing files/folders

Do not save just close the .zip and upload to your mobile sdcard, enter recovery, flash and enjoy.

Possible Issues and solutions:

You may need to remove the kernel in the Base Rom and sideload one more appropriate to your new Port Rom - flashtool is good for this

Recovery Crashes - error codes 6 or 7 are mainly caused by corrupted zips, bad partitions or poor coding in the updater-script file

Boot issues and strange video issues are mainly a cause of framework incompatibilities - try another Port Rom closer to your mobile hardware

I use this method for all my ports - the hardest part is finding a Base Rom, the next is realising the Port Rom can take hours of trials and errors

I never bother editing the framework files I just move onto finding another Port Rom closer to my Mobile Hardware

The least you mess about with the least there is to go wrong!!!

If you are very confident and can work with open .zip files on the fly you can perform all the above without the need to extract much other than the build.prop

Simply with the 'drag and drop' method between the two open .zip files

This possibly won't work for Miui as that requires a little more editing and work

: : UPDATE : :

This method can be done on either a windows or mac computer - I have successfully done it on both

Due to the latest Android 5.0 versions having extra compression this method may no longer work

In principal it could work however you will need other software to extract the compressed system files now compiled within the rom

Thanks to wine (mac) you can run this software however at this point the procedure is taking too long to complete, so I have given up!

Hope this helps someone