I have gotten mac shadows out of the glued palettes before this way. I used a big pan and heated it on my burner on hi til it got hot. then i put my palette on it just long enough to get the glue to melt. you can tell if its melted enough as it will easily come out. I used a needle so i could depot a color that had shadow left and tweezers could break it. I was careful tho not to melt the palette itself. I did this a few weeks ago i had one shadow left from a old quad i wanted to trade it b2m and i put the shadow in a old 15 pro palette i had a few spots left it. It worked wonderfully. Im not sure it matters but i used a old non stick pan to do this.