I think you'll have to give it up for a day or so if you want a fix in terms of replacement...or get the work done on a weekend. The hangers are easy enough to get ($$$ at the dealer, but might be hard to chop them off a junker at a salvage yard), but you're looking at some time to drop the tank to get at all the rivets and remove it all, not to mention possibly sawing off the front eyelet bolt and replacing it along with the bushing inside. If the other side is just as bad, it's a lot easier to do the passenger side, but same kind of work removing it from the frame.
With new hangers, new bolts, new bushings, it could be done in a day if someone really went at it and had all the tools and all the parts were ready. Might be worth looking at the shackles too, and seeing what shape they're in if the hangers are that bad.
The other alternative, which will take hardly any time at all, but cost you some money for labor, would be to have the hole ground out, and new steel welded in.