The gang at iFixit have torn down the 13-inch Retina display MacBook Pro. You can find the complete teardown at http://macte.ch/2ZcE5 .
“The 13-inch MacBook Retina is slightly more recyclable than the 15-inch Retina,” says Miroslav Djuric, chief information architect, iFixit. “Once inside, it took us only 15 minutes of prying to remove the battery, and we didn’t puncture the battery cells. It was definitely a doable feat (compared to nearly impossible for the 15-inch Retina), but still a far cry from the no-adhesive, non-Retina MacBook Pros.”
He adds that the 13-inch Retina’s design is a step in the right direction, but it’s a very small step: the RAM is still not upgradeable, the exterior screws are still proprietary, and replacing the display will still cost an arm and a leg. Accordingly, it earned a 2/10 repairability score from iFixit — a meager one point higher than its 15-inch sibling.