Ryan Jensen, AKA Instructables user jensenr30m, wanted to get at the magnet wire in his his transformer in order to make a relay. It turns out getting into those things can be pretty difficult; they’re not made to be opened. Ryan shows how to use a putty knife and hammer to force the core apart. It’s surprising how much magnet wire you can get out of a transformer!
How to Easily Disassemble a Transformer