You literally have to smash them open, I could be wrong, but I seem to remember the last one I took apart being brushless.
I have no idea as it was a couple of years ago I changed mine.
But being a bit curious, when things break and after I have fitted the new one I like to open them up to see if they could have been been fixed or what went wrong, and I remember it being a sod, so it got tossed!