Upgrade path for 7.9 to 8.0

What is the proper upgrade path to take a 7.9 project and move it to 8?
a) Install 8 on a clean machine and restore 7.9 GWBK to it?
b) Install 7.9 on a clean machine, restore 7.9 GWBK to that, then install V8 over the existing GW?
c) None of the above?

Thanks…