do u mean the round blanking plugs , about 1 " round ?
I think there was a post about this some were , but I carefully drilled the centre dot of the plug with a thin drill bit , prob 2 / 3 mm , then screwed in a self taping screw and pulled on that with pliyers
use caution when drilling / u can easily drill straight thru

and make a hole !!
prob either come straight out easy or be a reel pain un stuck sold
a tap with a parallel punch and small hammer to shock it a thou , prob help . All down to how much rust ect holding it in I guess.
worth the effort I think to know that all the seals / o rings are changed .
I cant remember it there held in , or if they just pull straight out m8 sorry , prob just the give in the rubber holding them in .
hope this makes sense tom
Some mornings I wake up grumpy, but most mornings I let her sleep in.