Are you familiar with the basics of using Innerspace & ISBoxer? Or are you looking for a fully detailed guide?

As you mentioned "Rift is not on the list of games", it is with the new update.

Update IS to developmental build by Right-Clicking the IS Icon in the System Tray (after you've started IS), and selecting Configure.
From the IS Window that pops up, select "Use Developmental Patch" (or something like that). Click Apply. You may need to close IS and re-run it. It will update.

Update ISBoxer to version 38 (I think). The option to Update ISBoxer should come up automatically when starting it. If it doesn't prompt you to update, there should be a link to updates within ISBoxer, on the Bottom-Right window right after you've started ISBoxer.

Let me know what you need and I'll see what I can do from work.