Hi, The seat is held in with an "o" ring. It will be tight on the "o" ring, a bit of a waggle usual frees it off. (after removing the single cross head screw and the small "fork" that holds the seat in position.) If you have new ones to fit, howk the old ones out with a pair of long nose pliers, but only if you are scrapping them, as the long nose pliers might damage the brass seat. Steven.