I like using a bench vise. I like to remove the driveshaft and press the u-joint out in the bench vise. Also if your replacing one you might as well replace both U-joints. There is one on each end. For the cost it is worth it.
Just remove the driveshaft and replace both u-joints and then put the driveshaft in. If your concerned about pressing out the u-joint yourself. I am sure a local machine shop will do it for you for a small fee. Or even a local mechanic shop.