How to remove spindles from a cut string
Square tenon and dovetail spindles
Often, spindles are tenoned into the tread.
Removal of the return nosing with a thin blade stripping or chisel knife, will reveal the spindle extending into the tread. The return nosing may have been glued in place as well as pinned, so you will need to be careful when you remove it if you are planning on re-using it.
If it is stubborn, gently prise apart using a thin, wide blade. Insert a second thin, wide blade. A third blade or chisel can be tapped between these giving protection to the tread and return nosing.
The spindles are usually nailed into place and can be removed by tapping the rear with a hammer. Take care when using the hammer to avoid damaging the tread or string.
You may find that the spindles have been glued into place and require a little more persuasion to remove. Cutting the spindle will enable you to lever it out. Be careful not to damage the tread or string. Use the hammer to gently tap it from behind whilst levering.