You can remove this lens with virtually zero risk to the LCD underneath:
Get a couple guitar picks or spudgers ready, and another old spudger. Using a hot glue gun, glue the old spudger into the very middle of the lens. Let the glue cool completely.
Using a heat gun pointing up from the bottom, heat the 3 edges of the shell around the top and sides of the lens. Avoid getting heat on the lens or hot glue as it will soften.
Using the spudger as a handle, pull up on the lens to get the top edge started and get your guitar picks/spudgers under the sides at the top of the lens.
Complete removal as above.
Using a spudger/guitar pick, start to peel an edge of the hot glue loose to remove old spudger from lens; then clean any residue with alcohol.
You can remove this lens with zero damage to case or lens:
Using a hot glue gun, apply a bead of glue across the entire lens but not on the body of the iPod. Move the nozzle back and forth in the glue for about 20 seconds; this keeps the glue hot and heats up the Apple adhesive on the other side.
Quickly jam an old spudger into the hot glue and hold it until the glue starts to harden; this will happen quickly. Gripping the spudger and digging into the glue over the spudger with the fingernail of your forefinger, pull straight up evenly but firmly. The lens will release pretty easily if you time it right; otherwise it will pop if it has gotten cold.
I’ve done a dozen of these this way successfully.