MacBook Pro: How to remove or install memory - Apple Support
Upgrading RAM in Your MacBook Pro 13" or 15" : 19 Steps (with Pictures) - Instructables
Is there a way to upgrade the RAM in an early 2015 MacBook Pro without voiding the warranty? - Quora
Apple 13in Retina MacBook Pro review (2.7GHz, 256GB, Early 2015) | Macworld
Memory in New $1099 iMac is Soldered and Not Upgradable - MacRumors
A-Tech 16GB Kit (2x8GB) RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Surprise! iFixit says you can't do much to fix or upgrade the 2015 MacBook | Ars Technica