How to Replace Soldered RAM on MacBook Air (13-inch, Mid 2012) - YouTube
APPLE MACBOOK AIR A1466 (2012) 13" INTEL I5-3427U@ 1.80GHZ 4GB RAM NO SSD LAPTOP | eBay
Amazon.com: Odyson - Logic Board 1.8GHz i5 (i5-3427U), 8GB Replacement for MacBook Air 13" A1466 (Mid 2012) : Electronics
A-Tech 8GB 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
Upgrading RAM on a First Generation MacBook Air - YouTube
MacBook Air 13" Mid 2012 Teardown - iFixit
Apple MacBook Air 13" A1466 2012 i5 1.7GHz 4GB RAM Logic Board 820-3209-A | eBay