Just change the pump out.
Keep the same housing.
The filter attached to the old pump clean (with clean gasoline)and reuse. The one that comes with the Focus pump won't fit in the Contour housing.
I had to reverse the wiring. Nothing really hard....had to trim a tab on the inside of the harness.
You will understand once you see it in person.
The trick to the ring is when removing it.....DON'T BEND IT!
One more thing....once you are ready to do this....drive you tank down to almost E.