The "J" clips are a pain, but follow SgtTaz's advice and you will get them off - pushing down on the cover/foam above the area you are removing the clips to release the tension, at which point you can start prying it off. Once you figure out the first one the rest go quickly
Some pictures of the J clips along with the *old* style (95-02) seat (similar in construction) in various stages of disassembly are available here;http://www.p71interceptor.com/heatedseats/
You might be able to access what you need to from the underside of the seat, though. If you haven't already, I'd remove the seat from the vehicle. It's easy and will make the project a lot easier.
Don't forget the reconnect ALL connectors under the seat on re installation or you will get airbag warning codes / lamp.