Believe it or not, the hardest part of this job is getting the grips off of your existing handlebar. You don't need a work stand for this simple job.
1. Loosen your shifters and brake levers and push them inward as far as you can. Force a skinny screwdriver under your grip and spray a little AquaNet inside. They'll slide right off and you've got the hardest part done.
2. Loosen, but don't remove the face plate from your stem and slide the handlebar to one side. That'll make the next step easier
3. Unless your new handlebar has a lot of rise, just leave the cables connected and slide the shifters a brake levers off.
4. Remove the old handlebar and install the new one. Don't tighten it yet.
5. Slide the handlebar from one side to the other and loosely install your brake levers and shifters. Don't tighten them yet.
6. Rotate your handlebar to get the sweep-back angle correct and tighten the face plate. If it was my bike I wouldn't worry about buying a new 4-bolt stem or even using a torque wrench with the stock Hard Rock stem. The torque spec is 15 - 20 lb/ft. That's pretty tight but not all that you can manage. Imagine a 20 lb weight hanging off the end of a foot long wrench.
7. Stick a nickel inside each handgrip. That'll keep the handlebar from cutting the end out of it. Spray a little Aqua Net inside and slide the grips onto your handlebar. Rotate them until the graphics look right. By tomorrow morning the Aqua Net will have set up and they'll be nice and tight.
8. Locate and tighten your shifters and brake levers. You'll probably want your shifters and brake levers angled about 45 degrees from the horizontal.