1) start by loading the song you want to recreate
2) send it to the ACW to extract the chords and tempo map it
3) when satisfied with the timing, exit ACW and send it back to RB
4) go to the chords window and fix any chords that aren't what you want.
5) Once timing and chords are right, start adding RealInstruments. Experiment to see which ones sound most like the instruments in the song.
6) continue until the backing instruments you've added play along well with the original song that is still loaded on its own track

at this point you should have the original song on one track, and your own generic version of it on other tracks. You still need the hooks.

Many songs play the hooks while the singer is not singing. If you crossfade the original to come forward during instrumental passages, and bring your tracks forward when the vocals kick in, you will end up with a song that is basically a vocal redux, but with no artifacts.