My .02 is......
Don’t mess with any that aren’t leaking thru.

If it’s only the one that’s leaking...... “what I would do” is mark the top of the guide so it can be reinstalled in the same orientation to the hole.
Push it out, clean the guide and hole thoroughly with carb cleaner, reinstall guide with the guide and hole coated with green loctite.
Let sit overnight.
Use black “right stuff” around guide top and smear some in the hole of the spring cup.
Install a valve and spring into position while the right stuff cures.

The seat should be touched up with a stone to insure concentricity to the reinstalled guide.