The metal lines are normal I think, and as long as you can't see the pins facing up, you've got it in the right way
When you get the processor, the therml paste should already be below the heatsink, and is like a square strip with protection on it keeping it cold and wet. As soon as you take that off, you put the heatsink and fan ontop of the processor and clamp it.
If you wanted to change the paste, you'd then scrape the remains of the other one off carefully, and then reapply on the paste. Filling the entire chip in a thin layer and then placing the heatsink on top.