Installing a backplate if your case doesn't have a hole

[hexagonsun]

What's the best way to install a back plate if your case doesn't have a hole? Obviously you will have to do it while the motherboard is out of the case, but what is the best way to position the motherboard so you don't damage it?

 

[hexagonsun]

Ah ok, I hadn't thought of that, I was thinking of turning the motherboard upside down and doing it that way but was worried something might snap or get damaged some other way.

Do you mean literally slide it or place it on the table and put the motherboard over the top? I imagine sliding it could scratch something?