I found the best way of bending them was to use the soft lip of a green wheel bin. That way once you have bent the correct angle, you can just drop them in and close the lid.
just playing
I've now had my mats for a few months, and I gotta say I simply love them I haven't fastened them to the floor with either screws or double sided sticky, and they're not sliding back and forth. They're not slippery either, even when wet. Obviously I haven't tried them in snow yet, but I'm counting on them being nonslippery even under those conditions. They're also much easier to clean than the original rubber mats, not to mention the rough shag (insert pun) you lot have in your cars. So there