Remove Stuck Beaters on a Mixer

Here are some quick fixes for beaters on a mixer that won't budge, no matter how hard you pull at them.

Steps

Drip a little household oil or vegetable oil into the join between the beater and the shaft or sleeve in which it is inserted into the mixer. Give this a few moments to drip down and jiggle a little. It should come loose after a little movement; wiggle it off gently in a straight line.
Try a heated towel. Another method is to wrap a hot towel around the shaft for 10 minutes, then pour more hot water over the towel and wrap again for another five minutes on the mixer itself to heat up the metal. Wiggle the beater off in a straight line.^[1]
Keep the beater sleeve loose in future. Regularly oil the sleeve to ensure that the beaters do not get stuck in the sleeve again. Use a food grade oil in case of drips in your ingredients.

It is very important to wiggle down in a straight line to maintain the alignment of the shaft and the beater and so as not to bend any of the beater blades.^[2]
If you accidentally bend a beater blade trying to remove it, press it back into shape with the base of a teaspoon. Press it onto a chopping board or other solid non-slippery surface.
Some suggest using WD40 to lubricate the mixer beater receptors.