The oven xD just turned one of the burners on and held it over it until it was hot and soft enough to work with.

You've gotta be really careful though, as you can burn your hands pretty easily this way, I kept just passing it over the flame to avoid holding it there and burning my hands.

I've heard you can also use a hairdyer though as they get quite hot if you hold it on one spot long enough, not tried this method myself though, so you'd have to experiment with it first