I just got a new toaster, and when I was going to open it, I discovered that the screw head is not a standard one; I’ll need a Torx key to open it.
In case you don’t know, a Torx key is exactly like a screwdriver, except that instead of a flat head or an “x” head, it has a six-pointed star on the head. No fancy technology; just a tool that not many people keep in their tool kits.
So the question is: if I get hold of a Torx key and just unscrew the toaster and then put it back together again, would the fact that I’m using a relatively uncommon tool be enough to make what I do a maaseh uman so that the toaster does not need teviloh?
No. There is no special skill involved in unscrewing that screw; it is only an uncommon screw head.
On Chol Hamoed, you would be permitted to unscrew it letzorech hamoed.