Ford Repair: ford E150 axle seal replacement, gear shaft, pinion shaft

Question
i am trying to replace the axle seal on my 1995 for E150 van. brakes are off,diff cover off, looks like i need to loosen the small screw holding the verticle shaft holding small gears to push down on the shaft so i can get at the c clips holding the shaft in place. i cannot remove that screw.i am using a 5/16 socket which seems to be slightly oversized but isnt slipping.do i need a different size socket and more pressure, or am i going about it all wrong? is that short verticle shaft the pinion gear shaft? please help.  thanx

Answer
Hello and thanks for the question...I'll try to help.
 Nope, you are doing it correctly. You need to remove that bolt (5/16 OR 8mm) and remove the pinion shaft pin, release the C clips on the ends of the axles, and take them out.
Get the small lock bolt to a good position for you to work on and then put the truck/van in Park......this will lock the rear end.
Hope this helps,
Erik