When sleeves are too long, remove stitches from the bottom wrist of both sleeves, making sure material is not damaged when you do that. Use a seam reaper and it will be much easier. Take out the cuffs but stop short of reaping the stitches just before you reach the buttons and button holes so as not to disturb these areas. Cut the sleeves to desired length and sew back the cuffs in place. You may want to hand baste stitch them first before using the machine.