Describing the procedure in words is a little difficult, but basically you are going to tighten the spokes on the side of the displaced portion of the rim. Look closely at how the wheel is built. You will see how tightening the spokes on one side will pull the wheel to that side and visa versa.
Word of warning....make changes in very small increments. 1/4 turn at a time, max. You will need to set up some way to measure the runout. A trueing stand is best, but most of us don't have that option. I've used the axle in a stand, or even on the bike holding a stationary pointer to pick up the runout. Give it a try, just take your time and think out each move. If you have any buddies in the bicycle world, they are often adept at wheel trueing, as it is a normal part of life for them.