The age of your bike, most likely has a screw on freewheel.
By spindle are you talking quick release?
Take it to a bike shop, ask them to replace the neccessary part, and to redish your wheel to work with a single speed screw on freewheel.
If it's not a screw on, then get a hub conversion kit from chain reaction, cost not alot and comes with all necessary bits (spacers, cog and lockring.)
The age of your bike, most likely has a screw on freewheel.
By spindle are you talking quick release?
Take it to a bike shop, ask them to replace the neccessary part, and to redish your wheel to work with a single speed screw on freewheel.
If it's not a screw on, then get a hub conversion kit from chain reaction, cost not alot and comes with all necessary bits (spacers, cog and lockring.)
easy.