Two ways to do it.
Fire a shot at a mark, then with the gun held steadily in place, aimed at the same mark, without moving the gun, you should be able to adjust the scope so that the crosshairs are lined up on the bullethole. The scope should now be pointing where the barrel was pointing If the gun moves from where it was pointed for the first shot, the adjustment will not be right.
Unless you have a vise, it is probably just as easy to use the clicks on the scope. Measure the distance up/down, and right/left from point of aim to the hole, then turn the adjustment knobs the required number of clicks for proper alignment. Most scopes will have the # of clicks per inch and direction on the knobs.
Either way will usually take several attempts. It is usually best to fire a group and adjust from the center of the group rather than firing single shots and trying to make up adjustments that are also compensating for all of the combined factors of rifle accuracy, shooter ability, wind, etc.
hope this helps,
bergie