Turn the jeans inside out and mark the desired length with pins or chalk
Measure how much length needs to be removed
Fold the jeans up to the marked length, keeping the original hem at the bottom
Pin the folded fabric in place all the way around each leg
Try on the jeans to confirm the length and fit
Remove the jeans and press the fold with an iron
Sew a straight stitch close to the original hem to secure the fold
Trim any excess fabric if needed, leaving enough allowance for the seam
Finish the raw edge with a zigzag stitch or serger to prevent fraying
Turn the jeans right side out
Press the hem again for a clean finish