shaking wheels when driving

i have a 94 voyager 3.0l and my wheels shake when the van moves. when i jacked up the van the tires off the ground i shaked the wheels and there moved, not still. Could this is that the balljoints have worn out and need replacing. And is this job easy for a do it your selfer to tackle at home in my own garage. And how much would this cost me to repair parts + labour.