Question How do I remove the side panel off of my Phanteks Enthoo Luxe

You do mean "does not seem to becoming off" - correct? Likely a typo but do need to make sure that the problem is correctly stated.

Go to the following link:

http://www.phanteks.com/assets/manuals/PH-ES614L_Western.pdf

Verify that I identified the correct manual for your case.

If so, panel removal information is in Section 8, page 15.

If the link is not the correct manual, search Phantek's website to find the correct manual.