@technonicx user Hello, there is no version on lineageos 15.1 published on the internet (from lineageos site) so I do not recommend using Custom ROM. I had some problems, I installed beanstalk ROM on my phone, it was turning off by itself and I was trying to turn it on, and in some ROMs it might not work in some things like camera. But if you still say I'm a crook. 1) Install TWRP on your phone but be careful you may not recover if you break your phone. 2) Download the version you want from the internet to install ROM on your phone and download The Open GApps Project for Google apps. (Select the version you want to install according to the Android version of Arm) 3) Start your phone in TWRP mode. 4) Make a backup of your phone against any problems (problems caused by the system), choose everything. 5) Then choose wipe> Advanced wipe dalvik cache, cache, System and data options here, and scroll right to the right below. 6) Come to the Install section Come to the ROM where it is, select the ROM, then scroll the arrow to the right, after completing the installation, select the gapps file and scroll to the right. 7) Start your phone from the Reboot System section.

@technonicx user Thanks for your interest and answer, but according to the information I got as a result of my research, this kind of transactions; Although it is very risky, I have decided not to throw a ROM for now, as there is a possibility of irreversibly damaging the phone. Although LineageOS is up to date and highly recommended, I don't want to take risks. So when I buy a new smartphone, I can install the current version of LineageOS instead of shelving my old phone. Even if it irreversibly spoils the phone, at least I will have a problem because it will be my old phone.

@technonicx user I did not have any problems while doing the backup, but when installing TWRP, yes, it was livable, I experienced it once, but I fixed it with LG up software.

@technonicx user There is no ROM to P10 Lite or even Huawei phones because there is no Custom Recovery for Huawei. There are a few exceptions. The name of that phone is Honor View 10.

Maybe you are insterested