Just to point out:
1. Do not press again the locker.
2. Changed the bottom RAM first.
3. Put nicely, gently to the slot. Cue for you. You must see the label of the manufacture.
4. Close everything.
5. Switch the Mac and check "Finder>About my Mac" show the correct RAM.
Once they have, you'll be able to view a graph of their reputation gained over time.
Here's a preview of what the graph will look like:
No reputation gained yet.