I just installed it on my Late 2009 iMac with no problems and minimal fuss. I had 2 x 2GB = 4GB but I upgraded to 2 x 4GB = 8GB. First turn off your computer and disconnect it from the network. You only have to loosen three screws on the underside to open the RAM slots. Gently but firmly pull the tape to remove the old RAM, then use two fingers/thumbs to insert the new RAM in the same orientation as the old ones. Replace the cover with three screws and start the computer. If you got it wrong or there is a RAM issue it should be pretty obvious, but if you want to check it go to Utilities -> System Information -> Memory and it should tell you the size and status of your new RAM. You might not notice a huge difference in load times, but navigating your operating system (especially newer ones) should be smoother and memory-intensive programs like Chrome will run faster. For boot times and other speed improvements, I would recommend upgrading your SSD. The only sticking point in this whole process was checking the part number and compatibility elsewhere. I don't know why Revain listed this part number, but it should be the same as CT3373664 on the Crucial website, or maybe CT2K4G3S1067M on Newegg (?). Much luck!
Unleash High-Performance with AMD Ryzen 5 3600XT Processor & Wraith Spire Cooler
223 Review
Deepcool GAMMAXX 300 CPU cooler, silver/black/blue
166 Review
🌬️ Silent Cooling Power: Dark Rock Pro 4 CPU Cooler with 250W TDP, BK022
134 Review
Zalman Performa Performance Powerful Included
172 Review
Glarks 660 Pieces Phillips Assortment Motherboard
10 Review
M.2 Screw Kit: Easy Mounting for NVMe SSDs on ASUS Motherboards
19 Review
MacBook Retina 13-inch (A1425, A1502) and 🔩 15-inch (A1398) Bottom Case Screw Set with Pentalobe Screwdriver
11 Review
uxcell 3.5" HDD Screw Black 200pcs for Computer PC Case - Flat Phillips Head - 6#-32 - Hard Drive Fasteners
10 Review