Curious that of all the cars that I have refurbished, the most recurring problem is an inoperative clock. Ironically, in my recent acquisition, the clock works perfectly. My issue is that the glass face over the years has accumulated a cloud of what appear to be moisture stains on the internal side. With my A/C unit blocking clock removal access without unit removal, I hesitate going through the effort of removing the clock. If I do remove the clock, is it possible to personaly disassemble and simply remove the glass face or do I have to send it to a speedometer shop like others have done?