If the four small rollers toward the bottom have turned to jelly, replacing the pick roller will not solve the problem.
I did the full teardown to replace the lower rollers. It was challenging -- the notes I made as I went along list 45 steps -- but the repair was a success, and gave me a big dose of that warm fuzzy satisfied feeling. That was more than a year ago, and the scanner is still running, with a current page count of 65,000+.