Don’t try to take it apart but hit it with some Deep Creep (penetrating oil) and look for burrs where it might have been dropped—smooth out any burrs with a swiss file
buying a brand new one is like hitting the million dollar lottery...wont ever happen !..lmao. unless you run across a NOS cap on ebay ?, you can bet your bottom dollar the seller will want a fortune for it !..lol. I went to plastic fuel tank on my '89 trx350D foreman, haven't looked back.I had exactly the same problem mate. The 'open close' bit on the top wouldn't budge therefore the tabs wouldn't pop out. Had to get a new one
Soak that puppy in any light oil and not solvent or vinegar the rubber does not like it.I tried everything and ended up buying one on ebay. It hasn't come yet so I hope I don't end up with THREE that don't work!!
Thanks to all