Pop the seals off the new bearing and visually check to see if the bearings have grease, if not pack them with waterproof grease. I know the Moose kit I bought one bearing had zero grease in side the bearing.
drill the carrier while the bearings are out, install a zerk fitting. Pop out the seals on the inside bearing, and inside seals of outside bearings. Put it all together, and grease the sh** out of it before installing.