I just repacked all 4 wheels on my trailer 2 days ago. I also replaced all the rear seals. This was the 1st time I did it on my trailer. I found some spindle nuts were loose and thers were too tight. All the bearings, races and spindlesvlooked good though as I do not put a lot of miles on my trailer.
I loosen the wheel lugs and then place some 4x4 cribbing under the frame close to the leaf springs. I then use a 20 ton bottle jack and jack up the trailer just until the tire can spin. follow suit with the other 3, doing one at a time. Once the tires are back on I spin the wheel as I pump approved grease into the EZ Lube zerk fitting. With a new install it took aprox 72 pumps to get the grease to fill up the hub and come out the dust cap. It was the same on all 4 wheels. About 1.5 tubes of grease for the 4 wheels. Took me abut 2 hours for the entire job. I also inspect the brakes and tires while they are off. I found a tire with some deep cracks in the tread area. I swapped that one out with the spare until I get new tires next year.