So, you're saying that there are no separate supply lines to your faucets and toilets? Only galvanized pipe?
If that's the case, I would unscrew the galvanized from the faucets, toilets, etc., and then unscrew it from the next nearest joint. If the galvanized section removed was longer than a few feet, I would either transition to Pex and install in-line shut-offs, or screw in a shorter piece of galvanized pipe and add 1/4 turn brass/steel shut-offs and use braided steel or flexible nylon supply lines. If the removed section is relatively short, I would just add the 1/4 turn metal shut-offs and braided metal or flexible nylon supply lines.