Front part unlatches but rear one stays connected; don’t want to break anything.. let me know ..

 

My '19 G550 cover is different than yours, but the attachment scheme might be similar. Photos below illustrate the cover tabs that have metal spring clips that go into receptacle slots on the adjacent air filter covers. If you have a telescoping inspection mirror, you should be able to see the rear-most tabs from behind the cover, and determine if they're in the receptacle slot, or if they're mis-aligned and jammed. In this event, maybe you can free them with a screw-driver using a bit of lateral pressure. If they are in the slots, try prying straight up. As long as you don't twist or leverage the cover, the spring clip should release without damaging the plastic post that they're attached to. Try lifting the front part of the cover slightly to see what kind of attachment scheme is used -- maybe it's totally different. Anyway, hope this helps.

Engine Cover

Metal spring clip on cover post

Receptacle slot

 

Thank you!

im astonished, no one knows for g63...wow! I couldn’t find anything on the web either. My Range Rover was sooo easy...