The flat portion, resting against the sole, is joined via velcro.

The part under the front, the rubber piece, is glued on.

 

I detached it using a 1/4" flat bladed screwdriver, in order to have the shoemaker replace the flat rubber with leather.  It comes detached every once in a while because I only attach it with the velcro. the hard part is to GENTLY detach the front part. pry with the screwdriver or an even smaller 1/8" blade VERY CAREFULLY!

 

FYI I'm referring to the non-sliding shoe (for me the right one). (The left shoe, the sliding shoe, doesn't have a cap.)

 

I have a pair and unless you are willing to risk messing up the shoe, I recommend buying a new tip and taking it to a shoemaker.