Well, I installed the belt today. First I removed 3 bolts (3/8″) that hold down everything (last picture).
Then removed 4 bolts (3/8″) from the pump thing. This is how you get the belt on.
Then put the belt around the plunger then around the small gear. Then roll it around the large gear. Done!
Misc. information about the compressor:
To order the belt just call 1-888-895-4549 and ask for the 007-0068 belt. It is the only belt they ship / sell, so it is easy.
Kobalt (aka Lowes 99007 vlk1582609) 26 gallon air compressor manual: http://www.powermate.com/productmanuals.php
So I just removed the Piston from the large gear. It has some built in holes so you can place a bar inside to brace it, then use an allen wrench with optional breaker bar addition. Move the piston, slip off the belt.
Hunting this thing down in town is a pain, Kobalt service center didn’t even know what the part was or which place actually made the compressor.