You can pull them apart and swap the foam. Also, your drivers seat might have torn foam around the frame. I'm replacing my foam currently (I actually think the stock seats are pretty comfortable). It was allowing the seat to sit lower on the left and causing discomfort in my hips. Anyway, here are some pics...I'm ready to do this too. I have the washers on my work bench but the ones I got are much larger, almost the exact size of the plastic spacer.
The thing I noticed is that the bolts that came with the spacer kit (that are installed right now) do not appear to be long enough to handle 1/2" height of the washers so it's back to the hardware store to get bolts that are 1/2" longer.
One thing that is frustrating me is how the driver's seat is soft and much more worn out than teh passenger seat, which is nice and firm and practically new. I wish there were a way to swap them.
I glued in some more fabric to help support the foam over the edge of the seat frame.
From what I can tell, the seat foam is symmetric from pass side to drivers side. The only difference appears to be where the seatbelt cutout is and that would be easy to replicate. I actually have two sets for seats right now, torn apart in my garage. Believe it or not, my factory seats (I assume) were both passenger side pieces. Same number and everything. The Drivers side with passenger foam did not have any relief cut for the seat belt and it fit fine.


