The switch body often snaps together and can be pried apart, has small screws, or sometimes rivets which can be drilled out.
This is more true of older switches than the newer ones. Things used to be made to be repairable. Now everything seems to be made to sell you the next one.
My recent switch repair was a slide switch that stopped making contact. Those can usually be taken apart and tweaked. Turned out this one was a double throw switch so all it needed was a lead removed from one terminal and soldered to the unused terminal. If it dies in the future there might be one of the right size in my parts piles or at least the right size is known.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)