RM-hacks on RM2 3.16.2.3

I bought the RM2 and am very happy with it! I've read about rm-hacks and am interested in using it.

My RM2 is on 3.16.2.3 and if I understand correctly I need to downgrade to at least 3.11.3.3 for the latest release of rm-hacks. (source)

I know you can use RCU for this, but it looks like the latest version of RCU only supports versions 1.8.1.1–3.14.1.9. (source)

Could anyone advise me on how I could downgrade? There are no important files on my RM2 yet, so maby a full reset is possible.