For the M18x R2 I could remove the plate, because the fan was underneath and kept cool those memory chips. I believe the M17x has the same design. The fan is below the GPU and has a hole to blow through.
For the 8 Beeps, there is a custom Bios for the M17x R4 that also unlocks the advanced menu. If you don't want to mess with this, you must set your laptop to full UEFI mode in Bios.
First set UEFI boot and then install the GPU. If it boots, just install OS again and custom drivers.
If it still gives you 8 Beeps, then probably you have the g-sync model. VBios is not to important. I had success with dell, clevo and HP Vbios and GPU booted just fine.