Use suction cups to pull the glass panel away. It is held by magnets.
4 slots supporting up to 16GB of 1333 MHz DDR3 SDRAM. Apple Technician Guide iMac (27-inch, Mid 2010)
Use a soft, non-abrasive surface to protect the glass and display when removed. Key Disassembly Steps Use suction cups to pull the glass panel away
T6, T8, and T10 are necessary for most internal components. Apple Technician Guide iMac (27-inch, Mid 2010)