I am like Floyd, I use a mini torch I got from Radio Shack to remove the end cap, and either my big Weller or my big Craftsman soldering gun to reassemble. I also use rosin core solder. Almost all the fluxes are corrosive and they are a pain to neutralize!
Thanks for the tip on the iron, my good one disappeared, I guess it grew legs and walked off. I had it since 1972.
Bill