Here is a simple device you can build to remove stud type earrings that have become difficult to remove. I invented this device out of necessity when both my daughters had their ears pierced and a slight infection in the earlobe warranted temporarily removing of the earrings to help cope with the pain. It is simple to make and is most effective. You will need a bolt, a wing nut, and 2 staples or something equivalent to be used as hooks. Note: I used 2 staples as it was readily available and if used with caution, should not pose a risk.

Step 1: Build

Simply drill a small hole at each wing end of the wing nut large enough to accomodate a small hook. I used 2 staples for my hooks.
Slip the hooks in to the wing nut and screw the wing nut into the machine bolt. Make a dent at the end of the bolt in the middle.
I drilled my dent though you tapping a nail into it should work.

Step 2: Remove Earrings

To remove the stud type earring, you want to unscrew the bolt enough such that you can slip both hooks (staples) into the loops part of the earring. Then slowly start screwing in the bolt until the tip of the stud falls into the dent of the bolt.
Now simply continue to screw the bolt clockwise while holding the wing nut steady and you will efectively be pulling back the loops off of the earring without placing any stress on the earlobes. You will find that even the most stubborn earring will come off effortlessly.