This happened to me. I took all the inside of it out such as the sellves and then the rubber sourrounding it. The then took out the screws holding the inner panel. Finally used a small rubber mallett and NOT hammered but pushed the dent outwards. I doesn't look bad.
If you are going to do this then take your time, don't rush the job and make sure you check just how much is being pushed out. I got the someone to press the front of the dent with a flat plastic chopping board.
The other idea is to buy a dent puller but they are usually too big.
Shamsudoha
January 2010