Marskid

I have a Windows 10 N40L like @hansel with Moded firmware from 2013, original onboard NIC, 8Gb none ECC RAM, Sata expansion card & AMD Graphics card for HDMI output. I have a spare flash drive and new 4xHD ready. I would like to wipe it and install CLEAN DSM 6.2.3 Guessing first thing is to change bios to TheBay. Will I be able to use the gfx card or best to pull it out ? Can someone Please provide the steps I need to get 6.2.3 installed or point me to a working guide.