I have an Delta model 600 single handle shower valve that wants to drip and is getting worse. I have the repair parts but the dome nut is stuck and I, of course, don't want to bust the valve body trying to remove it. Any suggestions from someone that has faced this? I found a couple videos on the subject. One suggest heating with a torch, one guy used a dremal to slice it, one guy says tap on it, that hasn't worked. Method 1 & 2 would be an all in deal. Once you start that's it you're in it till the end, even if that means replace the valve which is then a major project with no water to the house till its done. Any recommendations?