Seriously, when my lens slips, I just do this:
Put a bunch of cleaner/rewetting drops in.
Gently "scoot" the lens toward my cornea by repeatedly lifting my eyelid away from my eye - looking in the direction I want the lens to go - then closing my eye and looking where my lens is.
For example, if your lens is stuck "above" your eyeball:
Pull your eyelid away from your eye - look down - close your eye - look up... repeat this several times and the lens will eventually drop out of your eye. Be patient, keep your eye well lubricated, and never go "digging" for the lens.