You can pop the dust seal off both sides with a jewler's screwdriver, pull the plastic ball cage out (only comes out one way, you'll see the slots to grab with the jewler's tip), push the seven ***** to one side, disassemble, clean and regrease the bearing, no problem.
It's Napa part number 6203 2RSJ for either idler or tensioner pulley bearing. This is a more expensive bearing and only time will tell if it was worth the $16. There are cheaper 6203's, like $6.
You can push the old bearing out of each pulley quite easily with a socket, vise and hammer. Doesn't take much tapping, just note its position and copy that when you reinstall the bearing.
You need a 15mm wrench to loosen the tension to get the belt off the pulley and the same wrench removes the pulleys' bolt. The bolts are long, so be patient.
I carry a spare idler pulley (with a re-packed bearing), spare bearing and a new belt.
When mine left me on the side of the road (totally my fault) the tensioner pulley bearing disintegrated and ruined the tensioner (where the pulley bearing rides) and shredded the belt. So, I carry everything but a new tensioner, go figure.