It should be pretty easy and just pull right off. If you don't have a set, get these so you don't damage the new ones! https://www.pinballlife.com/interior-cabinet-protector-blade-set.html

Holy crap!! Simple item. I trust myself, but I’m human and make mistakes. I slightly Scratched my Metallica side art.

This would help.

Fairly easy, but be prepared to remove any stuck on residual glue as there will be some. You need the sides of the cab flat and free of any imperfections before installing the new ones. I find it easiest to remove the playfield completely - which admittedly on JJPs is a pain in the butt compared to the stern spike 2's

The best adhesive remover you'll find: https://www.amazon.com/gp/product/B01MSFD50H/ref=ppx_yo_dt_b_search_asin_title
Use these plastic razor blades to scrape the residue off after soaking with the above: https://www.amazon.com/gp/product/B07Y1HFX7G/ref=ppx_yo_dt_b_search_asin_title

Followed by surface prep: https://www.amazon.com/gp/product/B006RMQCFW/ref=ppx_yo_dt_b_search_asin_title

And finally I use this following the surface prep as overkill (can also be used for wet application method, but I do dry): https://www.amazon.com/gp/product/B006RMC8J6/ref=ppx_yo_dt_b_search_asin_title

I then use some clamps to hold the side art in place and get it in position:https://www.amazon.com/WORKPRO-Woodworking-Light-Duty-Quick-Change-Spreader/dp/B0928LM8XG/ref=sr_1_4_sspa

And I apply it using these felt squeegee's to lay it flat starting from the front of the cab to the back: https://www.amazon.com/gp/product/B01DY6SXHS/ref=ppx_yo_dt_b_search_asin_title

Yea, it took me destroying one side of my Dialed In! art blades to finally get a set. Now I rarely lift the playfield without them!

Have replaced on a Spooky pin and they pulled off clean. Have replaced on a Stern and they did not pull off clean. Took hours with a razor blade and goo gone to deal with the mess. Nightmare. Have not replaced on a JJP.