The easiest way to remove votives or tarts from their holders is buy filling your sink or basin with aboiut a half to an inch of hot water, set holder into water for a few min. and the will readly pop out with a bump of a butter knife.  If you tart burner is all one piece, light you tea light, give it a min or two and it will be easily removed.  Be sure to use a paper towel as the very bottom may be hot.  This works on Jar candles as well.  I remove the remain wax, and recycle it in my tart burners.  No waste here.