There are lots of you tube videos on this. My favorites are Peggy Seagers, from Silhoutte Patterns and Angela Wolf, make sure when you measure in how much you want to take you do it equally, that means if you want to take in 2 in on each side, then that's 1 in from the part of the leg and 1in from the back leg panel. You divide all alterations across all seams. Then mark where your pockets are now but in where you'll sew. Good luck