Replacing Front Output seal on T Case

[Chulisohombre]

Pretty sure it's a locknut. Impact as was said and pop out old seal. Use a socket same size as seal and slowly pop in the new seal with light taps with a hammer. Yolk and nut back on and i like to hand tighten back down.There is a specific torque on the nut but I think it's 65 ft lbs. if you don't use a new nut I oils put a little lock tight on the threads.