Every seal is a different and a unique challenge. The front seal is in the clutch throw-out tube and difficult to remove. A special tool is required to install the new one. I found a hole saw the right size and made the tool by grinding the teeth flat before using it to press the seal in the throw-out tube. You'll need to remove the front cover to do this. Remember all the bolts holding the front and rear cover on are threaded all the way into the gear box. they will leak fluid unless you carefully clean the threads and bolts and use a sealing compound on the threads. The rear seal is more difficult since you will have to remove the rear out-put flange. To do this the slotted nut must be removed. A special "pins socket" factory tool is used on the slotted nut. If your handy with a little grinder or cut-off tool you might be able to make one from the rights size socket. You will need to uncrimp the lock ring around the slotted nut before you can even get the socket in place. think about getting a new lock ring for re-assembly. The torque spec for the slotted nut is 87 ft/lbs and can be difficult to remove unless it has worked it's way loose over the years. There is a special factory tool for holding the output shaft flange from turning when your loosening or tightening the slotted nut. With a little imagination, you may figure out another way to hold the flange to loosen and tighten the slotted nut. Once the slotted nut and flange are removed the rear cover can be removed. Remember to seal the bolt threads before re-assembly. The rear cover holds the transmission rear seal and the speedometer cable drive seal. There is also a paper gasket to replace for the rear cover. I always use some sealer or gasket shellac on the paper gasket since I am sealing the bolt threads also. Once the rear cover is off, the rear seal can easily be changed by pressing or tapping it in place,
using the correct sleeve/ socket or what-have-you. The small seal for the speedometer drive is extremely difficult to remove and can be tricky to install. The small drive gear for the speedometer cable is pressed on its shaft and the shaft must be driven or pressed out before you can install the new seal. The old seal is almost impossible to removed. I suspect a special seal puller is used normally. I made mine by modifying an off-the-shelf internal puller with long slender legs. You cannot get behind the seal with anything to drive it out. If you had exactly the correct size reamer, you might be able to machine it out. Be sure to install the new seal in the correct direction (spring end first). You must drive or press the speedometer drive shaft in exactly the correct distance as previously installed when the seal has been replaced. There is a very serious hidden danger when the slotted nut and output flange have been removed. You must avoid rotating or disturbing the transmission. The slotted nut keeps the internal gears, keys and synchronizers in place. When removed the internals can shift causing a miss alignment with a shaft key. Shifting problems will result. Of course, a special factory tool is used to prevent this also. You can make a sleeve out of some PVC pipe to keep the gear cluster tight while your working on the rear cover assembly. Simply use the slotted nut and the correct diameter and length section of tube to hold the gear cluster snug. The seal in the top shift cover is a different challenge. You have to disassemble all the forks, rods, springs, balls and spacer sleeves in the cover to get to the seal. There are some special nuts to unfasten which are deformed when installed and should not be used again. Be careful or you will have tiny springs and balls flying everywhere. Every fork and spacer must be returned to it's exact location during re-assembly. Considering the degree of difficulty, you might opt not to change this seal. It is at the extreme upper part of the transmission, far above the fluid level and not subjected to much splash. It never seems to be a source of leakage. If you decide to go ahead, stay in touch and do your research!
