Tappet screen

[Mickmorris]

FWIW.. I got myself the 1/2" drive slot bit (HMAN's post).
Had to grind it a little. Tool was shown to me by Knothead. I already had an impact like Mick referenced . I end up putting a 1/2"drive extension on the impact, held it down to remove slack from the chain of events about to happen. Smacked with a hammer.. out it came (loosened).

That’s exactly what I did to Ken. Worked like a charm. Improvise/Adapt/Overcome! Lots of solutions ya just gotta find the right one for your particular situation.