2h valve guide bush removal? Welch plugs?

[sodafeld1]

Stripping down 2h engine, want to pull apart, give it the best clean. Do you use a punch to remove the valve guide bush and tap it out with a hammer? Are they difficult to re-install?
Surely to give the best clean, the welch plugs should be replaced too?

 

[sodafeld1]

valve guide seal came off with pliers, leaving the guides for now. Says in manual to install by heating the head in 100c bath tub... they may be ok.

but little cracks in head leading from pre combustion chambers is more of an issue.
Think I shall give the welch plugs a fiddle as either they have to go out if cracks are repaired or the head is just a test dummy wreck.