XMA isn't a seperate style that sets up schools.  It is a program which school owners and subscribe to.  So basicly you need to find a school owner who has the program or is willing to subscribe to the program.  Try contacting this email:  memberservices@masuccess.com.   They may have a listing of schools in PR that have the program.

Other than that I would suggest going to the following camps that host XMA classes:

Camp Chat hosted at the US Open
Sharkey's Boot Camp
Sharkey's Summer Camp
AKA Wiinter Camp hosted by Matt Mullins and Sideswipe

These camps will are great for helping a wide range of people in XMA from the very beginners to the more advanced competitors.

I would also recommend getting Matt Mullins book/CD How to Trick which gives you step by step instructions on how to get some of the basic tricking down.  You can get that from Century or directly from Matt Mullins at http://www.sideswipepro.com/howtotrick.htm. 

I hope this helps.  If you have any more questions please feel free to contact me offline at martialscience@sbcglobal.net