My heater and a/c control unit does not display information thru the vf display panel. It does sometimes light up partially. I notice what seems to be a slight burn spot in the upper left side. Can the vf display panel be replaced by just taking off the plastic cover. When I try this, I seem to be able to pop the display panel out from the clips at the bottom, but not at the top. Is there a easy way to remove this and can you purchase a replacement. I have the 3 book service manual for the 1998 buick riviera from GM.