I'll do a quick run through, but any shop manual would have detailed instructions on this.
1. Manually push your wheels until they are facing stright. You have to align the steering wheel to the wheels later on so go ahead and get the wheels straight.
2. pop that black cover off
3. use the 10mm or 12mm to loosen the joint so you can attach it back to the rack. There's actually two of them (one upper and one lower) and it may help to loosen both so you have a little bit of play with the joint.
4. go inside and straighten your steering wheel. You might need to lodge something inbetween the weel and your seat to hold it centered.
5. Now go back under the hood (or you may be able to access it from inside the car) and slip the joint back on to the rack. You may have to twist it back and forth a little to get it to slide on. Make sure the wheels are still straight and the steering wheel is still straight.
6. Make sure the joint is even on both the steering column and the rack and the tighten the 10mm or 12mm bolts.
That's about the best I can do from memory. If you still have question, RTFM, it's in there.