[BLU R1 HD ROMs, Kernels, Recoveries, & Other Devel] kröte:
Proceed at your own risk. The following guide worked to Unlock the boot loader, gain root access, and install LineageOS 14.1 on the blu R1 HD version 9.2, Amazon prime, with allOfficial blu updates applied. Guide uses Windows 10.

The instructions below are meant to be used as a complement to the instructions already provided. Please read all the instructions provided by the operators and the Developers included instruction within the tools. if You can't figure out how to complete a certain step then you probably have to research using Google to find a solution. Try watching videos on YouTube so you can visualize instruction and also videos that show how twrp is used to install rom on android.

1-1st make sure the device can be connected to the Windows 10 PC using USB. The following link links to signed USB drivers At point number 4. https://xdaforums.com/t/twrp-how-to-root-newbie-friendly.3425677/ Download drivers. Extract files. Read Notepad instruction included in zip file on how to install driver in Windows 10. After installing drivers you should be able to transfer files from your computer to your phone using Windows Explorer.Also USB or adb is not working try different USB cable or try the official USB cable that came with the phone.

2- Learn how to activate developer options on your phone. More or less go to settings then to about phone then click build number a lot of times until developer options are activated. Go into developer options and activate USB debugging

3-You must also ensure your phone has the correct drivers to communicate with your Windows 10 PC using adb. To verify if adb and fastboot is communicating correctly between you computer and your phone, 1st learn how to use and install sdk platform tools from the following link: https://www.xda-developers.com/install-adb-windows-macos-linux/ .

Open Windows Explorer and navigate to the platform tools folder click on the address bar and type cmd. Now boot your phone into fast boot recovery mode using the Information in the following video:

now that your phone is in fast boot mode you need to type without the quotes "fastboot devices " In the Platform tools command prompt and your computer needs to list your phone as a recognized device. You can also Connect your phone to your computer using USB and type In The command prompt from platform tools "adb version" and "adb devices" to make sure everything is working.

to install the adb drivers follow the instructions included in the notepad file within the zip Listed below in step number 5.

4- Before proceeding you should have USB adb and fast boot working.

5- Download R1-HD-MTK-SU-unlock-tool-V2.zip Use the following link https://xdaforums.com/t/updated-unlock-tool-4-2019-for-all-versions-of-blu-r1-hd.3561333/page-20 and follow the included instruction to unlock your phones boot loader and gain root access. You have extract the contents of the zip file into the platform tools folder then double click the bat file. After completing option 3 the command prompt should tell you your boot loaders unlocked. After completing the last step you should gain root. You can Then reboot your phone andcheck if you have root access with a application from the android play called root checker by Joey krim.

6- delete the platform tools folder. Then go the following link to install lineage 14.1 https://xdaforums.com/t/2017-10-23-7-1-2-lineageos-14-1.3689435/. Download the lineage compressed file and the twrp image file and place them into a fresh/clean platform tools folder. Now your phone should be in fast boot mode Before proceeding. Follow the instructions in the webpage to flash twrp. Boot into twrp and to format and delete. Make sure to select all available options. Also wipe Format all data.

7. Now you can sideload the zip rom into the phone. Research on how to sideload. Use command adb push C:\platform-tools\Lineage-14.1-20210313-R1-HD.zip /sdcard. Then go to install in twrp. Don't skip the important format step. Install the rom. Then sideload gapps and install gapps. You should have previously Downloaded gapps From the Internet https://opengapps.org/ into Your platform tools folder. To choose the correct gapps the architecture of the r1 hd should be arm. And the correct version to choose for lineage 14.1 should be Android 7.1.2. the pico package offers the minimum Google apps this may help save space on the phones small hard drive.

Now In twrp select reboot and your phone should restart and you should have lineage 14.1.