Apple Intel-based iMac (Mid 2007) - Manual (Page 37)

Chapter 3 Boost Your Memory 37
11 Replace the memory access door using a Phillips #2 screwdriver to tighten the screw.
12 Holding both sides of your iMac, return it to a standing position, and then reconnect
the cables and power cord.
13 Press the power (®) button on the back of your iMac to turn it on.
WARNING: Remember to replace the memory access door after you install memory.
Your iMac won’t function properly without the memory access door.
Raise
stand
Memory
access door
Phillips
screwdriver