Warden, the prechamber is put into the head from the top side.. so no problem taking it out that direction... two pullers are available... one impact ..like a dent puller... and the other a screw mechanism... one or the other will take them out fine unless something physical has happened to really damage them...

On the ball being really really round.... LOL... if you put something with small projectons on it in a container and heat it and turn it around and around a million times... it will come out VERY ROUND....and smooth... think of the process of making stones smooth in a tumbler....