Install the replacement shaft: pull out the steel cores Fix the inner cores to the grinder with the included L-shaped wrenches Screw the shaft joint back to the grinder Slide the end of the inner cores into the grooves inside handle Push handle back onto the shaft This is a 36.22inch ( 920mm) rotary grinder tool flexible shaft, which is suitable for most rotary tool Strong metal ensures strength and durability for long lasting usage Suitable for fine polishing, engraving and grinding The rotating tool is very versatile, and this accessory provides you with more functions Dismantling the shaft: First, pull out the existing handle from the shaft Fixed with a spring load metal balls Unscrew the shaft joint clockwise from the grinder ( note that it is a reverse thread) Pull down the metal shaft outer to expose the steel inner cores Unscrew the inner cores from the grinder with an L-containing rod, Manufacturer: Kaeltsyn