IHI 28N Boom Slop

I have an older IHI 28N. The boom pivot (highest joint on the boom assembly) has a lot of slop. It easily swings from side to side. There is a pin and bushings that I need to get to and probably replace. This is wear is probably from using the bucket to smooth dirt by swinging the boom from side to side "smashing" the dirt around... The excavator was a rental unit before I purchased it (Hurricane Katrina cleanup in South Mississippi...). So, I'm looking for advice in getting the thing apart and checking for things to repair. Are there tricks/ways to safely separate the boom parts, protect hydraulics, etc. as I investigate the problem. I'm also interested in finding out if there is a reliable part supplier preferred by you guys. Thanks in advance.