How do you put a seal in front differential? It is leaking fluid.

It should be okay for a short time, depending on how bad the leak, but you should replace it as soon as possible or it will leak out all the differential fluid which could cause damage to the internal parts of the differential. Usually you have to remove the wheel, brake assembly and axle from the side that is leaking and use a seal puller to remove the old seal then carefully drive the new one in and re-install the axle, etc.

Remove driveshaft and pinion yoke.. Remove seal.. Reverse proceedure to install noting new seal lip need to be pre-lubed before yoke is installed. .. Probably best to have repair shop do this as it really needs to be hoisted on a lift! .. Sure it's not a cv joint boot leaking this grease?? It'll sling it everywhere!