Usually the keys on most typewriters are friction fit on and come off pretty easily. The tougher part is that the slugs are soldered onto the typebars, so you'll need to remove them and swap them with a soldering arm. Even if you have the soldering tools, the more trying part is aligning them properly when putting them back on. Many old school shops have/had custom jigs made for properly aligning slugs when soldering them on.

If you don't have the tools, patience or facility, this is usually something best left to your favorite shop: https://site.xavier.edu/polt/typewriters/tw-repair.html

reply to u/fontinalispluma at https://old.reddit.com/r/typewriters/comments/1gb3dwc/change_the_keys_and_type_slugs/