i use a dremel with a carbide wheel. mark the arrow at the length to be cut, freehand cut before the line, leaving it about 3/32"-1/8" proud, square up and grind to the marked line with a sanding station disc wheel and 120 grit. inserts are glued in using slow set epoxy (waterproof, as opposed to 5 minute epoxy which is only water resistant). the epoxy saturates the "end grain" of the carbon fiber tube and seals it tight ... i make sure a thin film of epoxy goes up the shaft end, about 1/4" from the insert, for added bond protection. never ever had a carbon insert shaft failure due to normal usage.