If lp4 isn't the closest printer to you, then, for example,
What's going on?
lpq lpq -Plp3 lpc status
Get rid of a print job / all jobs / all jobs on all printers
lprm -Plp3 2779 lprm -Plp3 - cancel -a
Start and stop
cupsenable lp3 cupsdisable lp3
Of course, how much of this you can do depends on whether the print job is yours, and on whether you are the root user.