I'm planning on doing a coolant change on my 9 year old Phillips RPTV. I have the service manual and several links from topics on this board. The service manual says to remove the coupler from the CRT and then the lens from the coupler for cleaning. The coupler is held on by the four screws with the springs. All the posts that I've read only remove the lens and leave the coupler attached to the CRT. What's the proper way of doing it? Is the CRT/coupler gasket more delicate than the coupler/lens gasket? Is it possible to get replacement gaskets for these just in case? I have also read in a couple of posts where people put RTV sealant on the old gasket before putting it back together. Should this be done or not? The service manual does not mention using RTV sealant. Thanks.