I don’t want to rip them out. What’s the best way to shorten from the cast on edge?
How much too long are they? Are they already attached to the body of the sweater? Were they worked flat or in the round? What is the stitch pattern?
I’ve never done this before, but it seems like you could unravel (or snip?) the cast on edge and frog a bit from that end, then bind off.
I’ve shortened, and lengthened, sleeves from the CO edge a number of times (not all the difficult if you take your time and plan ahead as to what needs to be done) but it’s difficult to give advice w/o knowing more of the specifics of the current state of the poster’s project.
If you knit ‘bottom up’ you can’t frog from that direction (you’d have to unpick).