Complicated Alps are the easiest to reassemble, actually.
The worst ones of all are the "contact blade: big" Himake switches (AK-CN2/DN2, i.e. the standard Alps clone since the late 80s) as it takes a lot of effort to force the stationary contact back inside its recess, and you have to get both contacts correctly lined up with the corresponding groove and force it back together. Pretty easy if you're doing this with a loose sample switch, but terrible if it's in a keyboard. The friction is so bad that I actually tore a hole right through a switch with a screwdriver before the top would actually budge and come off. (That was a really old one.)
The worst of all is SMK second generation, as they don't go back together even when you're holding them. You've got the horribly fiddly SMK lintel contact assembly but with the baling wire construction. It's a complete nightmare and of my three loose switches, I just gave on with at least one of them. It's back together, but the slider won't fully depress any more, which is the same problem I keep having with the Himake switches in my MiniTouch.
The switchplate in complicated Alps makes assembly so much easier, as all the fiddly electrical contacts are solidly snapped together into a self-contained unit that's a perfect fit — neither loose, nor excessively tight.
