Apple's MacBook Pros with Retina display are remarkably thin, but they have been notoriously difficult to repair and users have not been able to conduct upgrades on their own. iFixit has just performed teardowns on the latest 13 and 15-inch MacBook Pros with Retina display and little has changed.
According to them, both models now have their battery cells glued directly to the chassis, which makes it difficult and also time-consuming to remove. This is unfortunate because as we know, batteries do succumb to wear and tear. In addition, the PCIe-based SSD used continues to be proprietary; and RAM continues to be soldered onto the mainboard.
At this point, it is worth pointing out that the Apple has stopped selling the non-Retina 15-inch MacBook Pro. This old model is not only easier to repair but users could also perform upgrades on their own such as the memory and storage.
All things considered, iFixit has awarded the new MacBook Pro models a "repairability" score of just 1 out of 10.