I'd strongly suggest not just replacing the starter, even if it's the problem. If he's lucky enough to have a denso starter, it's cheap and easy to fix, and you don't end up with some craptastic replacement or rebuild. It's not uncommon for the plungers to get gummed up and stick, the ring on the plunger to get too thin or beat down, or most commonly the contacts, all of which are an easy fix and the parts are available from toyota.
i had tons of starter problems so i took the starter apart and shaved down the contacts a little and havent had a problem since
