Yes you do, there is a special tool from Volvo and it is very expensive. You may want to consider taking it to a shop to have it done, or take the a-arms to them and have them press the bushings in/out, or look into buying the complete a-arm with new bushings.
One thing to note, it is very important that the new bushings are installed in the correct position!
My stepfather and i did it for his S80 in his shop with a vice, hammer, an impact socket big enough to fit on the metal rim of the bushing without peircing through the rubber inside, and a wrench to hold that socket in place during pounding.
First Remove the control arm and lock it into the vice. make some marks on it where you take the old bushing out so that you dont forget the proper orientation of the new one when it goes in. apply some very thick lubrication to the outside shell of the bearing and after you get it lined up and fit the socket over it, start tapping away on the socket with the hammer. little by little it should squeeze the bushing in and after maybe an hour or two of work (with two people) the whole job should be done.