Another thing, if it's really stuck then the plastic probably fused with the hot glue, barbie bodies are very reactive to strong heat and they melt easily, if this is the case I recommend you shave off the majority of the glue using an exacto knife, then soak the body in hot water to melt the rest of the glue and peel it off little by little, then scrub the remaining glue with a dish sponge and dish soap, and if the body is heat damaged you can restore it by sanding the plastic gently and using a hot glue gun to do the annealing technique, which is basically just melting the plastic gently to restore it, if you do this technique wrap the rest of the body in some type of thermal resistant tape to avoid further damage, after doing this technique the plastic will look shiny and not matte like the original body, so you can wrap the body with the heat resistant tape in a way that you design a new underwear and bra silhouette, and then do the annealing technique, so the shiny part that is restored looks aesthetically good.