You can shorten the post by cuting them off with a hacksaw or in a lathe, drill and re tap the cut off end for 3/8-16 thread and put a pc of threaded rod in the end of the shaft and drill a hole thru it to allow the wires to go thru. The portion that was inside of the number plate bracket will thread directly into the signal light. Use a 3/8 jam nut on the new end inside of the plate bracket.
