To take things apart, you will need to disconnect the u-joint at the differential. The rear section of the shaft can then be removed, it comes apart at the splined joint. Then unbolt the bell collar at the tranny, and unbolt the carrier bearing. The front shaft and housing should slide off, if it isn't welded together.
I would assume the rear bearing in the tranny needs replacement, possibly more in the tranny. Because of the heat, I would recommend replacing the forward driveshaft. If it were me, I would locate a tranny and forward shaft from a 55 to 66 truck. The tranny will be the same except set up for an open shaft. It shouldn't take to much to install the open shaft, length might be of some, but you can safely use about an inch of play in the slip joint. If it's more than that, go to a driveshaft shop for some work.
If you want to keep the truck original, you will need to check your tranny for damage, and get a salvaged ball collar, shaft housing, and driveshaft. The u-joints can be bought at a local parts store, the carrier bearing and rubber bushing from one of the on-line parts vendors.
