First things first. Remove its source of food and seal up its entrances to your house. This is the only long term solution.
For direct removal to be used in tandem with the above advice, use your choice of:
1) Use a small live trap baited with peanut butter followed by either release or euthanasia.
2) Use a strong snap trap, again baited with peanut butter, placed against the wall.
3) For a humane and reusable (but somewhat expensive) kill device, look into the rat zapper
http://www.amazon.com/Agrizap-inc-RZU001-Zapper-Ultra/dp/B000BWFESUI don't have any experience with it but it seems to have good reviews.
>>344865BAAWWWWWW