"Sport seats" are either the 2 tone leather or 2 tone leather+cloth
see:
http://www.mrandmrs-g.net/SGFOG/catd-inttrim.htm
As for getting inside the seat - I think I saw it in the WIS somewhere.
Generally:
-edges of the bottom part are just stretched on the frame - if you look at them you will see that they're easy to remove
-on the back there is a "plate" (one with the pocket) that is held on the sides by push connection and on bottom by the elastic tapes - see the tutorials for repairing lumbar support (**** WARNING seats from 03-04 are a bit different and have extra material on bottom, 05-> are more "open" on the bottom and easier to open/close)
Main part of the upholstery is held by small metal rings that are a pain in the... fingers
I recomend cutting or bending them with pliers and using plastic zipties instead (just make sure that "lock" of a tie is hidden in the foam afterwards)
btw. there is a lot of them - for rear seat (bottom part - I changed the upholstery to fit foam with cupholder) I used ~80 ties and it wasn't all places like in stock
Here You can see the rings in the rear seat (they're also inside - where the stitchings are).
Please make a DIY with pictures when You will be working on the heating pad exchange, I also have to do it because drivers seat is cold while passenger is warm :/ and its hard to drive when sitting on the other seat
