Fairly easy job. Make sure you clean everything and inspect the spindle for wear.
It's a two bearing setup, one is pressed into the hub, the second one is held in place by the big washer and nut on the outside.
Getting the old bearing out of the hub can be a pain. Be careful not to scratch the hub surface.
The big washer should just barely move (use a flat-blade screwdriver) when the nut is tight.
I like to tighten the nut by hand, then use a screwdriver in the slot to give it a "whack" by hand. That usually gets the nut right where it needs to be.
Andy