Galaxy A8 2018 | Custom Rom 'link'

Power off your phone. Boot into by holding the Volume Down + Volume Up buttons simultaneously while connecting the phone to your PC via a USB cable.

The developer community has provided several excellent choices for the Galaxy A8 (2018), depending on your preferences: 1. LineageOS (Stock Android Experience) galaxy a8 2018 custom rom

Tap seven times until a message says "You are now a developer." Power off your phone

Boot into Download Mode: Press and hold buttons simultaneously, then connect the phone to your PC via a USB cable. Release when the warning screen appears, then press Volume Up to continue. then press Volume Up to continue.