Put strips of tape on the edge, peel it away and then use a piece of tape to pull the dust off the back of the protector/screen. Repeat until perfect.
I tried that for around 5 minutes straight after, the protector wouldn't come off! But maybe it's because I only used one strip. I thought I'd just make it worse if I tried and more dust might have gone in so stopped trying. But you're making me want to try again.
Damn this thread!!