replacement ngpc screen protector

Bought one of these of ebay as its the first ive seen made of glass.

https://www.ebay.co.uk/itm/Real-Gla...ffff6785|iid:1&_trksid=p2481888.c100675.m4236

Is it best to remove the original from the back and push off or with a little heat, loosen the glue and use a pick to pop it from the front?

Is that a replacement screen or just a screen protector?

I got some of these not too long ago and they are great. I love the glass lenses for Gameboy so I was happy to see NGPC ones were available. I used a small knife to carefully lift at a corner and pried the old one off.

Btw you might save a few bucks buying from this sellers web store instead of eBay:

https://www.mortoffgames.com/index.php?route=product/product&product_id=915&search=Neo+geo

All fitted and she looks lovely, shame to take the old one off as its been with me since new and has travelled all over the place.