You only have to remove the front bushing to install the Okie bushing/seal. The original rear seal/bushing is 6 inches back, but the Okie bushing/seal is 5 3/4, so you'll end up with both in there. Disclaimer, my truck is a '52 so there may be a slight diff in dimensions.
Look around, you should be able to get the Okie plus the tool to remove the old front bushing for less than $200. One vendor was about $90 for the bushing and $65 for the puller if memory serves.
Relatively easy if you've been into the driveline of one these trucks a time or two. Even if you haven't but can follow instructions, are patient and use common sense it shouldn't be a problem.
