repiping with copper
It's a challenging job, I would remove all the galvanized pipe if possible. I don't like running into decommissioned wire and pipe when I'm on a job. You have to think about the next guy coming to do work in the future. A tip for making the connections. Get a flame shield and keep a pail of water close by. Also pre-tinning the pipes can be helpful in those really hard to heat places.