Some guy who's racquet I strung has come back and said he would like it tighter. From 19lb to 22/23 lb. It's only been like 2 weeks, so I am happy enough to try for him. He is also happy to pay for a full restring if I can't do it. I've never done it before though. Anyone got any tips regarding undoing the knots? And I'm not sure an extra 3/4 lb will gain me enough string to re-tie knots afterwards. It's a 2 piece job, so I can leave the starting knot of the crosses. Would be best to only undo 1 of the mains knots, and re-tension the mains side to side?