I was a Spendor dealer and removed the grill many times. If you can grasp the edge of the grill with your fingertips and pull back it should come off.[Pull Hard!] I have had to resort to a small knife at times but use care. As the other reply said , what are you going to see when it is off? If the speaker sounds good the drivers are working, the only thing you would be able to do is to push on the center of the woofer to see if it is rubbing; I have never encountered this in a Spendor. If you have a test disk you can do a frequency check , but I wouldn't think it was necessary.
