somebody makes a die (file trim) that is hardened so you can just file off the excess case length. i have in the past done this just by hand using a set of calipers and some slow easy filing. another way to do it is if you have the lee trimmers, IF you have a pilot that is the same size (or close) and shorten them by hand a little at a time. not the preffered way of doing things, but sometimes, you just gotta do what you gotta do.