I'm not sure what size the socket is, but I know on my D80, a standard impact socket is too large on the OD. The socket had to be turned down on a lathe to fit.
as far as tightening, you will not be able to use that method. too much variable with the new nut and washer. You will need to use a new nut and washer. the nut is a pinch type... one use only. Also, you will need a two jaw puller to remove the yoke from the pinion splines. Hopefully you have access to a beefy compressor and a very strong air gun, such as the IR 2131.
I have replaced the pinion seal a couple of times on my truck, with 58k on the clock. One piece of learned experience... go to dodge and get the factory seal. They are short money and worth the couple of extra bucks.