I got my 27" iMac EMC 2639 SSD upgrade

Sorunum

to replace my 27" iMac 1TB HDD with Samsung 850 PRO 512 SSD

Tamirim

It went perfect; thanks to iFixit guides and videos

Önerim

take your time to prepare for this, a clean area and quiet place will help a lot. handle the screen with extra care, and there's no actual need to remove the left speaker completely if you just intend to replace the HDD with an SSD