After 8-10 hours of burning, with the fragrance evaporating with every burn, eventually you will start to detect a drop in scent throw and may wish to change your wax melt. You must make sure that the wax is cool and hard before attempting to change your melts. Light your tealight and allow the wax to soften at the edge of your burner.  You can then simply take a paper towel and wipe into the wax. It should come away easily. You can then dispose of the paper towel in the bin.