I have removed the left side of the front suspension, and am replacing the bushings. The car has a 15mm front sway bar, and I dont know how to get the bushing the goes through the sway bar out?

Those bushing don't go through the body if memory serves me correctly.

Simply just remove the three 13mm bolts that hold the mounting plate in place. Then do the same with the plate (of course the arm attaching the bar to the link must be taken off).

You may have to separate the bushing from the plate, slight heat an some lubricant should do it. With the mounting plate out of the way check for a cut on the bushing, pry it open and yank it off.

Installation is reverse of removal, just make sure the bar is centered before tightening everything up.

so you dont have to take out the gas tank, all you do is take the bolts out on one side, and work the bushing out.

You got it. The bushing is coned shaped, if it were put from the inside of the car it would eventually slip and fall in the gas tank area. It is sandwiched between the body and that triangular plate you see. It is quite stuck in there and getting it loose will probably the hardest. The only time I think the gas tank has to come out is when you are installing a sway-bar on a car that didn't have one.

getting those things off is a major pita. and it's totally not necessary if you are happy with the size of the stock bar and the bushings are in decent shape... leave it be if you can...