Spouts generally come in two types: screw on or push-on. A push-on one will have a set screw to keep the thing aligned. A scew-on one won't.
You can take the existing one off and shorten things as needed. Keep in mind that if it is a screw-on one, you have to measure very carefully, if you make it too short, you might not be able to tighten it down enough to prevent it from leaking! If it is a press-on, just loosen the setscrew push it back, then retighten it. If you are unlucky, the setscrew was originally tightenend too much, and deformed the pipe, and the seal when you push it back just aligns with the deformed part. If so, then you'd have to remove the pipe and replace it or buy a different spout that had the seal in a different location so it missed that area.
If you need to solder things, use the real stuff, don't try the epoxy or whatever...it will create problems down the road if you ever do need to service it.