I've just started using two Canon HFG25's for my business, and need to get the footage into FCP (6.0.6). My operating system is Yosemite 10.10.5.

I guess I need to import the footage and then convert to ProRes, but not sure how to do this! At the moment I can't even figure out how to import the MTS files from the camera onto my external hard drive!

You need to open the whole AVCHD package file in FCP Log and Transfer. Dont try to split out the MTS files by themselves. Also, I think AVCHD works in FCP6 but I'm not 100% on that...