Start with the bakugan open. First, I used a size 2 (dunno what this is, maybe mm?) screwdriver from an electronics tool kit to remove the two bottom screws. The screwdriver slips a lot, so I would suggest if you're going to be disassembling many bakugan, find the real screwdriver.there is none. after long long long checkng on the internet i realised triangle screws are the tamper resistant ones. (i know you guys know, i'm just dumb and it's all new to me.)so what you can do is make your own screwdriver using a bic pen and heating up the tip so its soft then you can poke it into the screw and mold a screwdriver for triangle screws =]