I have used the support page to change the install path but it doesn't work for me. For me, the path is "C:\Program Files\Oculus" and the "C:\Users\USERNAME\Downloads\OculusSetup.exe /drive=D or C:\Users\USERNAME\Downloads\OculusSetup.exe /drive:D" and "[drive]:\Users\USERNAME\Downloads\OculusSetup.exe /drive=[new system drive]" do NOT work for me.
This has been troublesome for many people. The easiest thing to do, (if you have room on C Drive) is install the Oculus software in the normal way. Then, before you install any apps, change the default install location for them. You can use any other drive to store the games and apps that you install.............
If this solution is no good for you, just search these forums for "install to a different drive". Quite a few people have tried to explain it to others.
i5 6600k - GTX1060 - 8GB RAM - Rift CV1 + 3 Sensors - 1 minor problem Dear Oculus, If it ain't broke, don't fix it, please.