Shorten Sleeves # 1

After marking the point where the sleeve cap joins the shoulder seam, remove sleeve from armscye.  Rip underarm seam as far as possible.    Place sleeves right sides together, slide inside sleeve down desired amount, keeping shoulder seam markings aligned.  Notice the amount of 1 1/2" will only hold true at underarm seam and cap top.  It will vary as the curve changes from cap to u.a. seam.

Shorten Sleeve# 2

After cutting off the one sleeve, it may be used as a pattern to cut the other sleeve.  The underarm seam may need to be taken in also.
 

Narrow Shoulders # 3

Many times the shoulders need to be narrowed too.  Using a French curve, find the curve & radius of the original armscye.

Narrow Shoulder # 4

Match the curve & radius to narrow the shoulder the desired amount.  Sometimes it may be necessary to take in the side seam just a bit to get this amount right, so the sleeve fits back in exactly.