Yes, you have to remove the bushings. Most remove enough of the rubber to get a hacksaw blade in the eye. Cut the metal tube that surrounds the old rubber bushing, being careful not to cut into the spring eye. Peel out the old metal.
I guess opinions differ on the best replacement. I have had the poly bushing squeak. I have read where some go to a bearing house and get impregnated bronze flange bearings the same size as the bushings and like them.