Similar to the microwave thing, but somewhat safer.. You could try using a hairdryer on heat and blow it at the affected part, test in bursts of thirty or so seconds to see if the part has heated up enough, but that should have similar and safer result than microwaving. (:

I haven't had to fix one of mine for this thankfully so I can't say Heating up the plastic will help, but this is simply a more convenient way to warm the plastic. (alternative to this would be use boiling water)

Good luck!