I guess no one has explained the two techniques yet to finish answering your question, so here we go:
There are two techniques: One is emulsion lift, the other is image transfer. Both can be done with several types of Polaroid color film, any of the ones the end in "9", like Type 59 or Type 669.
For an emulsion lift, the polaroid print is left to set up for about 24 hours or more after development. Then it is heated in hot water for about 4 minutes which softens the adhesive layer between the emulsion film and the paper back. The hot print is then transferred to a pan of water at room temperature. The emulsion is gently lifted/peeled away from the backing. Then it it placed upside down on a temporary receive and stretched/scrunched as desired. Then it is pressed down on the final receiver surface which can be anything, and manipulated to the desire final form.
There is two methods for the image transfer, one where the receiving paper is wet, the other where it is dry. I won't go into the details on this for brevity. For both methods, the film is developed for about 10 seconds, then peeled apart and the negative pressed against the receiver paper. It then sits for several minutes, then it is separated from the receiver. The emulsion actually transfers onto the receiver in this process. The type of paper used for the receiver is critical. Follow what is recommended in the books and you will save yourself a lot of grief.
Of the two methods, I find the emulsion lift to be the easiest to do. The transfer is more finicky and takes only to certain papers. With the transfer method though, you can also use the underdeveloped print for a lift.
I will be posting a transfer later tonight in the Experimental Gallery. Both are fun. Good luck.