If your lucky you might be able to get the job done without pulling the knuckle off the truck, but you'll be torching the old joint out carefully without cutting into the knuckle and then while things are still warm carefully hammer in the new joint without destroying it. There's no way to use a ball joint press with the axle in the way, hence the need to pull the axle and sometimes the whole knuckle.
Oh and did I mention you have to be lucky?
Sometimes it's easier to take the time to do a job the right way than to spend hours taking a short cut.
