Seeburg LPC 480 Upper Panel Speaker Grille Cloth

Hi, I am restoring a Seeburg LPC 480T. I am replacing all of the speaker grille cover fabric, top and bottom. The bottom doors are easy. I am having trouble figuring out how to get the upper panel open so I can access the fabric, remove it and replace it. I believe I have all of the Seeburg literature for this model, but nothing shows how to access or disassemble the top panel, or how to replace the fabric.
I would appreciate any help or advice.
Thanks!