I dont know how to reset one but I did learn a weird trick to make to swap an old drum and new drum.
On the side of the drum there is a little button about the size of a nickel, if you pop it out there is a chip glued to it. This must be where it records the drum life. If you move this button to another drum you can take a live a and dead drum and switch it...
Why would you do this?
Well it goes something like this. I bought a drum and it worked perfect up to the day the printer forced me to replace it with the REPLACE DRUM message. So I considered it a good drum and kept it, just in case.
Much later I was using a drum that lasted months and several thousand copies, and then started streaking. We dont print much to the printer so by date the drum was out of warranty. So to fix this I switched the buttons with the chips between the streeking drum and the old "good drum" that I had saved and boom I am printing well great again!
Now if anyone can figure out how to reset this chip back to zero we would be in business.