Put a thin, non-metalic if possible, pointy stick in to the 510.
I have used bamboo skewers in the past (but they may break and need cutting again to a point with scissors).
Remove batteries first.
Place pointy tip on edge of 510 pin.
Angle stick so it's side touches to top to the 510 screw.
Press down on the stick / prizeing the 510 up & AT A SLIGHT ANGLE.
Only do it bit.
Repeat again at the other side of the 510.
Keep working round from side to side until you have managed to raise the 510 up a bit.
Be careful and I stress I take no responsibility if something happens.
It is a long time since I have had to do this - back in the ego battery days before spring loaded 510's.