Originally Posted by Toe Knee

Assuming u got the head off mate, you have to remove the valves first, then with either the proper pliers(makes it easier) or any pliers will do literally grip em and pull em off!! can sometimes be a biatch but dont worry as their coming off so doesnt matter if u damage them!!! Then to put new ones on you just need to get a couple long reach sockets that are the same size as the new seals(from memory inlet/zorst are different size) and tap them into place with a hammer gently