[Sonny]

pcs50,

A sawzall with a long very flexible thin metal cutting blade will do by grinding the tip to a sharp point to punch thru between the glass panels and tube in the area where it's been glassed around then flex the blade and saw away. This is a poor method of mounting the under body panels to a mild steel frame and is usually done sloppy with general purpose resin and will have a lot of air bubbles in it to make your job easier. Try a good rubber hammer hitting the panels flatly to pop them loose.
GOOD LUCK