its not hard at all, i never did it before and i went under the car and could figure it out really quick. just make sure to get the right gasket seal and the right lube. buy the gallon version of the 90W or at the least a plastic pump so you can pump the new gear oil through the fill hole. fill it untill it dips back through the fill hole.
1985 THUNDERBIRD CFI 5.0L..
h-pipe, shorty headers, stock everything else
DEDICATED TO THE SURVIVAL OF COUGARS AND THUNDERBIRDS