Upgrading Android on GPD XD - Need Advice

I recently got my hands on a GPD XD, and I'm considering upgrading its Android version (currently 4.4, I believe) to at least Android 5.0. The main reason is to access apps and games that require a newer version, like Geforce Now, which doesn’t work on the current OS.

However, I'm worried about bricking the console during the process.

Has anyone here successfully upgraded their GPD XD? If so:

Can you share a guide or steps to do it safely?
Did you encounter any issues post-upgrade?
Do the gamepad buttons still function correctly after upgrading?

Any advice or tips would be greatly appreciated!