Ford F150 - Rear wheel bearings

So I am trying to troubleshoot a noise coming out of my drivetrain. Changed the u-joints yesterday, ran the engine with just the slip yoke installed to see if the tranny was the problem...it was not. So it comes down to rear end or rear wheel bearings. I am going to change the rear end fluid today. Last time I did it I didn't use synthetic (didn't think it would make a difference) and I didn't put any friction modifier in because its an open diff truck..didn't think that would make a difference either, but maybe it does?

anyway what is the best way to diagnose bad rear wheel bearings? How are they changed? I looke din my haynes manual but didn't see anything, I searched on here and nothing came up.

I put the truck up on stands and when I push on the wheel I can get it to click just a little bit on both sides of the axle. Is this normal or should it be tight with no play?

Thanks!
Berto