You cannot simply just swap the cushions. They're not interchangeable. Solscud is right, there is a metal bar on the outer side of both seats (left for driver, right for passenger) that supports the outer bolster. So you need a slot or hole in the foam for the metal bar to go into. You have to swap the seat pans too, but then the metal bar will be rubbing your center counsol. I installed my own heated seats and it doesn't look like you can "fix" this problem the way you are thinking. You would have to buy a new driver's cushion. What I did though, was fill the sagging parts with upholstery cotton filler to buff it back up. The foam was all crushed up on the bolster and the metal bar was poking through the foam.

 

I just recently purchased a new driver side seat cushion and installed it. It was easy and cost around 200 bucks for the cushion on line.

The job took about 45 min. and I can't believe the seats came with this much bolster when they were new.

 

That seems like the best idea by far to solve this problem. If you can just replace the worn portion of the seat and forget the rest, you should be fine. When mine get to the point of no return, that's what I'll be doing.

 

Where do you purchase just the seat side bolsters?

 

Try this:

http://www.hondaautomotiveparts.com/

 

It is possible to swap the whole seat base from one side to the other. Just remember to swap the seat belt clip over.

pie_n_chips has done it on his car in the last few weeks so PM him with a question!