Regards, David: You've listed some very good cartridges, your apprehension is understandable. For your consideration, I recently needed to do this with a Signet TK5ea, it too hummed, cartridge construction is comparable to your AT150. The ground strap is designed to accomodate removal for exactly this reason. It's a simple friction fit over the out pin, the tab is folded and then inserted between the cartridge engine and shroud establishing a contact ground to the shroud. If you have a "junk" cartridge you might try this on it first. Carefully work a precision screwdriver or hobby knife under the strap close to the pin, gently work one side then the other, it should start lifting off. There is no need to open the cartridge.