if you can change a wheel then you can change pads, its that simple
brembo's ?
just pull the clips out then the pins and remove the pads, copper grease the rear of the new ones
non brembo
http://www.350z-tech.com/zwiki/Brake_Pad_Installation
Spend the money on some upgraded pads and do them yourself, very easy, approx 1hr to do all 4
redstuff £109 for front and rear off CS
or go for ds2500 ferodo's
the oem pads are standard ferodo, i changed to redstuff and have not been disappointed
Opie recommend silkolene pro s, i use it
noticed the car was smoother revving and quieter on tick over when i changed to this
bought from opie - quality service
personal preference but i always use an oem filter