Kalika:
When you copied the files _inside_ planeshift directory, did you get a message saying:
"Do you want to overwrite files?" or similar? If not, you did something not wrong.
So you've to:
1) Decompress the .zip file (you've already done that)
2) See where the files have been decompressed to.
3) Select those files
4) Having them selected, drag and drop them inside your Planeshift Crystal Blue directory.
If a message asking you to overwrite doesn't appear, you did something wrong.
Please try to state at which step you felt lost, and we all will try to help you as best as possible.