Thetford toilet seat

Would anyone have an idea how to remove the Thetford toilet seat? Replacement seat/cover assemblies are at least $130 and the underside of ours is nasty from the previous owner (wife is grossed out), so thought I'd scuff and repaint it. The exploded view shows a pin on each side that runs through the cover into the seat and with a retainer clip of some sort. I don't see a circlip, etc. where it's supposed to be, but it's a little corroded in there. There appears to be a collar there instead. This toilet looks delicate and I don't want to mess it up, especially with the cost of parts. Also, if anyone has a solution for removing p stains, I'll try that first. Thanks for any help.

[tentcamper]

On my unit. if you look at the rear side of the seat you will see a steel pin that go's through the lid and seat. Along the inside edge of seat/pin you will find the c-clip. It looks like it would be a PIA to get off and back on.

[scrubjaysnest]

Ours is held on by screws you get at under neath after removing the whole top.

Thanks for the input. I'll fiddle with it some more.

I pulled the top off and removed the seat/cover assembly. There are two screws at the front of the base which go upward into the top. You need to remove these to release the top from the base front. As mentioned above, you can then removed the seat/cover assembly from the top by removing 2 screws from the underneath. It's amazing how little there is to this thing, hardly justifying the $600 plus cost and expensive replacement parts. Anyway, spent about an hour cleaning/bleaching the insides and then masked-off the seat cover, scuffed the seat and am in the process of repainting it. The circlips on the pins holding the seat to the cover are so corroded there's no doubt they would break-off if removed, meaning I'd have to find replacements. They're probably a non-standard size and $25 a piece from Thetford.

I made the mistake of picking the seat assembly up by the lid and watched the two pins break out of the back of the seat. The two holes are near the rear edge of the seat and are over-sized, so it didn't take much for them to break out of that pressed sawdust seat. Found a Bemis round toilet seat/lid assembly (pn 7m521ec) at Home Depot where the seat matched perfectly in size and nearly in color (you can get a white one for a few dollars less). Had to make a few modifications.
1. Removed the 4 oblong bumpers from bottom of old seat and installed on new seat since those on the new seat were shorter in height. Had to drill 4 holes to install the 2 bumpers at the rear of the seat since the new seat only had 2 bumpers at the front. I added a little shoe goo in the holes to keep them in place, and to make them more difficult to remove if I ever have to do so.
2. Removed the lid hinge from the new seat and installed 4 cap head screws into the naked holes on the bottom of the new seat.
3. The pin end that inserts into the seat is 3/16" dia. I found some 3/16" i.d. X 5/16 o.d. polyethylene tubing at H.D. to insert into the new seat's hole as a bushing for the pins. I think this will help strengthen the ragged hole and keep it from getting further wallowed-out causing cracks at the edge of the hole.
4. I drilled a 5/16” hole into both sides of the new seat for the hinge pin as near to the location as I could measure from the old seat. I used a drill press and spent quite a bit of time setting up the squareness of the seat in a clamp fixture. The first hole took most of the time. The second hole was not so bad. I suppose if you’re not interested in bushing the holes and just want to put in an oversized hole like on the original seat, you may be able to carefully do this with a hand drill. Just remember it’s a rounded edge with compound angles so you’ll want to take your time and center punch the hole first. I measured the depth of the holes in the old seat and matched the depth in the new seat by wrapping masking take around the drill bit so I knew when to stop.
5. With the 5/16” pin holes drilled in both sides I cut off a small piece of the polyethylene tubing , about 3/8” long and inserted them into the holes with a bit of wood glue, using the drill bit to seat them in place. You don’t want the bushing to extend from the hole because the larger 5/16” dia. section of the pin will interfere with it.
6. I reassembled the seat to the cover with the pins and original circlips (luckily, they came off without breaking) and all looks good. The only thing to be careful of is when reassembling the seat/cover to the toilet. Since there is no play now in the hinge pin holes in the seat, the rear of the seat may not want to sit on the two rear oblong bumpers, depending on where I positioned the holes in the up-down direction. I don’t want the pins to take the load when sitting on the seat so I may need to space the rear bumpers down with a shim to make sure the rear bumpers contact the toilet surface. If I’m off in the other direction and the bumpers want to bind relative to the pin position, then I can just shave the bumpers down a bit. Either way not too big a deal at this point.
So there you have it. A lot more work than expected. But wifey can now sit like a queen.