Here's how to disassemble a banister and balusters for refinishing. Using a block, gently separate the banister and newel post just enough to insert the blade of a reciprocating saw. Cut through the bolts and nails to detach the banister. Repeat this process on the opposite end. Then, carefully separate the pieces using the block. Be sure to number each piece for re-assembly later.
Here’s a way to get more life out of an old hacksaw blade. Mount it on the side edge of your workbench with about half the width of the teeth sticking up over the top surface. This will give you a handy cutting tool. Make sure that the location of this cutter is both easily accessible as well as away from frequent brush up traffic.