Did a quick search for you and came up with this - originally from gerard
Hi
Have ago your self! I cut a set of 25mtrs down to 20’s recently and they are ok. They don’t look quite like new buy they are strong enough so far!
1. Mark the length you want on the line with texter
2. Cut off old stitching using razor blade (making sure you don’t cut sleeve cause you reuse this)
3. Slide sleeve down past texture mark cut line to new length
4. Re sew using the same criss cross stitching like the originals ( I used 80lb fishing braid)
