pretty easy, just pop off the clips around the door card, remove the handle, and then pop off the handle brace cover to access the last screw. then peel off the sticky plastic sheet, be careful not to get the black crap on you or your clothes, it's a b**** to get off. look down into the door and unscrew the actuator.
there should be a guide in the how-to section of the forums.
get this and replace the gear instead of buying a brand new unit.
http://www.ebay.com/itm/2002-03-Maz...ge5&vxp=mtr&hash=item45fead1c9b#ht_500wt_1287
My driver's door had been broken since I bought the car last winter because I was too cheap to spend $75+ on the whole actuator. I found the plastic piece Brian_K linked to last week and installed it yesterday -- works like a charm! $15 is much better than $75...
trey