Reduce document to fit on 11x8.5 2up saddle stitch booklet

[Gregster1234]

I have a booklet that was sized to 8.5x11 and want it to 5.5x8.5 2up saddle stitch and the data is on it how would I reduce it to fit as a booklet saddle stitched before composing, I noticed that FP imposer doesn't reduce. I have 6 different versions of books that are each 200 records.

Thanks,

Greg