Is the terminal riveted or just staked to the buss bar then soldered, original windings. I am trying to reattach the terminal as it has come loose without removing the windings. I am guessing the best way to proceed is to unsolder the ends and remove the buss bar, clean and heat the copper so it's easier to work with then solder the terminal and reinstall.
I find it easier to remove the windings first. It takes a fair amount of heat to solder it back on and you will struggle to do that inside the starter case.
The terminal bolt is drilled, pinned to the buss bar and then silver soldered for strength. The original assembly is usually pretty badly damaged after failure.
Your procedure is fine, but you will need a 250 Watt iron for the soldering and cleanliness really helps. It is easier yet if you get one of these inexpensive assemblies and replace the original buss bar and terminal bolt entirely.
Ron the Coilman