I'm should let someone who still owes a D35 to answer this one. It's been so long, I just don't remember.
Ford 9" is non-clip... It's as simple as tires, brakes, 4 bolts for the axle retainer and it slids right out. The seal is tapped into the axle tube. Pull it out, put in a new one and reverse to process.
If I remember correctly the D35 has no retainer. Your got the pull the rear cover, push the axles in towards the center and remover the C-clips. THen the axles should slide right out (tire and all).
Someone help me out here.
On another note: a leaking D35 or even a dirty one should be replaced!!