howdy... sorry for not having responded earlier, I was away from a computer.

as far as taking the seat out, there's 4 bolts going through the seat frame, right next to where the height adjustments run. I found that if i look from the outside of the car, just under the seat itself, you can see the hex heads on the bolts. Mine were 12 mm on the front and 13 mm on the rear. I used an open ended wrench, you may be able to fit a ratchet in there. the inside bolts are more of a pain, i could only go about a flat or two at a time, between the overhanging seat cushion and the transmission tunnel. keep note of the materials that get released. sometimes the metal barrel the bolt runs through stays in place, along with the associated washers, othertimes the parts all come loose... depends on how much of the plastic guide is intact. it sounds confusing, but just take out one bolt, you'll see what i mean.

don't forget to unplug any seat heater! once all 4 bolts are out, the seat is still held in place by the height adjustment mechanism. simply pull the height adjustment lever to retract the locking fingers, and that releases the front then the back. getting it back in is trickier, but by trial and error, you should be able to get the same locking fingers back into the slots for the height levels in the under frame. I've found it easiest to do the back of the seat first, then once that is in, the front is pretty easy to get back in place. put the 4 bolts back in, plug in the seat heater.

I didn't replace the foam, just throw in a piece of carpeting, the plywood mentioned above, i used foam rubber. to go help support the seat foam. when i ditched the rotted seat grid, i used one of the 6 foot tie down straps, they're available at any hardware store, walmart or target have them as well. there's a ratcheting type, fairly big, 2 pieces. I went with a friction clamp, smaller, 1 piece. typically overpriced at $10 - 15/pair. I've had it in place for a few months now, and have been very pleased.

once the seat is out, maybe 5 minutes, 15 if you are easily distracted. ditch the grid, threat the strap through the springs, and pull tight. getting the seat out and back in, isn't too bad, count on 15 minutes to 20 minutes, hopefully without too much cursing. with all that, it may be easier to simply undo the bolts holding the rails to the floor... i've never done that, didn't know if there's a nutsert under the floor, or some nut just waiting to dissappear.

anyway, there's a long winded response to a few simple questions. good luck.