Also, it is a big PITA to turn the lock ring off. Be patient, work steadily. I used a hammer and brass drift and slowly, ever so slowly, with light taps, managed to get it off. I tapped lightly all the way around on the raised portion of the ring. You'll see what I mean when you remove the cap under the seat. Don't get too muscular with it.
Aloso, the seat can be a little tricky to pick up and you may break the plastic clip that holds it in. Mine was already broken by the alarm installer. I didn't know until I went to repair my pump.
Also, get a new o-ring for the access hole. The original one will br stretched and won't fit back in. The O-Ring on mine was green colored, if it matters. I repaired mine but you have to know how to do this. WE have o-ring repair kits at work. I recommend a new o-ring.
