Just fitted new cleats to my SPD sandals.
The old ones were coming up to 3 years old (several thousand miles of riding, and rather a lot of walking, as they're my do-everything touring footwear). I'd fitted them using copper grease on the threads and underside of the countersunk head, and hot glue in the bolt heads.
Digging out the glue was a 10-second job with a multimeter probe, and brought all the accumulated gunk with it. Three of the bolts then unscrewed easily with an allen key. The remaining one was a bit more stubborn and partially rounded, but succumbed to more careful use of the allen key. At no point did I have to resort to the socket set and hammer, or (god forbid) a drill and mole grips.
I fitted the new ones in the same way, a recipe I can thoroughly recommend to the panel.