You can usually slide a flat screwdriver under the black plug where it connects to the bulb by gently turning the screwdriver you can ease the plug off a bit.
If you pull the plug too hard there's a risk that the wire clips holding the bulb in place will give/bend and then it's a pain - try with the screw driver first first one side of the black plug then the other - once it's given a bit it'll pull off easier
