hey guys

i got this Hipshot D-Tuner Extender Key for my bass a while ago and while i was installing it the backplate bent. it's a Hipshot BT4.
i emailed the company that sold it to me and they said that they couldn't give me a refund or another one because i'd voided the warranty by installing it wrong (even though the instructions that came with it were for a different model)
and so the (solid steel) backplate has bent, meaning it doesn't attach to the headstock properly and it doesn't move freely, so it's basically useless because it won't work if it doesn't move freely.

so since i can't send it back anyway, i may as well try to bend it back myself before spending another £50 on a new one.
any tips for bending it back?
i don't have a vice or anything but if that's the only option i could ask at school

these pics don't show much but at least it'll give you an idea:

Rockin' shit