When a part is very stuck it is much easier and creates less damage to use a cake icing spatula to "Smack" the part right at the build plate with the edge of the spatula blade. For tall items I use the wooden handle end to smack the top of the part. This won't work well for toys and figures, but for mechanical parts it works very well. If you are using glue can can also remove the glass from the printer and run it under hot water.. the glue dissolves and the part comes off. Too stuck normally means your first layer is too compressed and starting Z offset is not set correctly for your current layer height.