[Appointments+] Key file does not exist (Google Cal)

Hey guys, Im getting really confused with your instructions for syncing A+ with googles API detials, I think the layout with googles control panel may of changed since you wrote the instructions?

After eventually finding the bits I needed to make the OAuth etc im stuck at one thing:

Google provide you with a .json file you download and place on the server to authenticate, but you guys say it should be a .p12 file? I need the 'Key File Name' which according to the WPMU instructions is the name of the downloaded file that we place on the FTP in the Key folder, but thats not working for me, probably because its a .json not a .p12?

Have google changed the way they do this? from .p12 to .json? Or am I looking in completely the wrong place?

Please help.