Hi tj
I did this with two Pronto TSU 9600:
- carefully remove the label at the back (with a Swiss Army knife)
- remove the two small rubber feet and remove all the screws as well
- then remove the sticky back panel
- clean the back panel from old paint
  (I used a pan cleaning pad for doing this, it took some time but was worth it)
- clean the back panel with cleaning solvent
- spray the back panel with a plastic primer spray
- spray the back panel with a color painting spray (2-3 times)
- spray the back panel with a clear painting spray (I used a not shiny one)
As color I used „platinum“ since it is similar to the look as the Pronto, but you can use any color of course. The final clear spray is acting as a protective coat for the color paint. I used „dupli color“ painting sprays since they are sold locally.
I made this a year ago, the back panel still looks like new and the stickyness is gone forever :-)