I've done some looking into this as I just got my first LS1 car, and it had the same cooked grease issues.

The real crux of the matter is the bearings are rated for 12,000rpm, but with the pulley sizes the A/C idlers are at that speed when the engine is at 4,000rpm and the main idler is maxed at 4800rpm. :| No wonder these cook their grease in a hurry when you are having fun.

I'm am currently working with Shon Herron to come up with something to solve this problem once and for all though.

Are any of the bolts reverse thread?

Re: Wanna maybe save $80? LS1 idler pulleys.
 

to reply to pulley rehab use spray on brake clean and spray into the bearing @ a45degree angle so the propellant spins the bearing fast clean up then re pack and be on your way this is my first post ever on a computer so ive entered the 21st century ! hope this is of use to someone long live the Z28!!!!

Re: Wanna maybe save $80? LS1 idler pulleys.
 

just my two cents, you can use a knife to pry off the seal. Worked great for me, and i think its easier than a screwdriver.

Re: Wanna maybe save $80? LS1 idler pulleys.
 

Did this on my 3rd LS1. Updated 1st post with more pics and info.