BTW That is the Carrier Bearing also referred to as the Center Support Bearing. You will have to unbolt the U shaped bracket from the cross member and remove and separate that drive shaft. Take the section of the shaft with the carrier bearing on it to your local machine shop and have them press the old bearing off and press the new one on.

When I did mine the machine shop charged me $20 for the pressing and I only spent about 1 - 1.5 hrs actually working on the truck.

This is really a pretty simple job.