The technically correct way to change the center bearing would be with a bearing splitter and a press, but I've changed a bunch of them on the side of the road with a big hammer and a heavy punch to drive the old one off, and a piece of pipe the right size to slip over the spline and drive the new bearing on with the same BFH. Quite often, a failed bearing has northing but the inner race left on the driveshaft.
Jerry
