I've posted in a few other threads like this as well, but have not received an answer yet. I've read that if it's the front diff pinion seal, you just disconnect the driveshaft and remove the pinion nut (impact gun helps). Remove/replace seal and torque nut back (impact gun or pinion flange bar) and reconnect driveshaft.
I asked because my front seal is barely seaping, but enough to make the bottom of the diff wet. If it's not a big job, then I'll do the seal, but if it's anything like having to retorque the crush sleeve....I'll just silicone the base of the seal for now.
2004 Ford Ranger 4x4 XLT.....4.0 V6....4.10 rear
2" torsion key crank
235/85/16 Goodyear Duratracs
Gibson exhaust (POR20 coated)