How do I change the oil

You have to jack it up to get to the drain plug. Be sure you obtain the correct oil for your toilet, the oil for the newer toilets will not work in the older toilets.

TDD

For sure. I put the old style oil in the new 1.6 GPF toilets at church. Now, the women slide off the pot, and fall on the floor. They need synthetic oil. But, I can't change it for another 2,985 flushes. Oil change good for 3,000 flushes.

I converted all mine to synthetic oil. It can go 10,000 flushes.

Apropos of nothin' in particular... I was having some problems with the toilet running because the flapper would not go down properly. A little investigation noted that the handle flipper jobby thingy was sticking in the full up position. I little WD40, a little jiggling the handle (etc), and all was well again.