Removing guides without boring them out to a thinwall shell is risky business. Once the guide wall is around 1/16" thick, a simple driver mandrel in an air hammer pushes them out easily. I learned that trick while rebuilding air cooled Volkswagen cylinder heads, but it works well on any engine with removable valve guides.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!