Truing process of the wheel has begun. The shorter spokes (near the brake drum) control the axial run out or the hop in the wheel as it is turned. The long spokes (near the spinner) control the lateral run out or the wobble.
In order to remove axial run out, spokes at 90 degrees to the section needing work have to be loosened and the ones at the area needing work are tightened. Obviously, tightening the spokes moves the rim towards the center.
To remove the lateral run out, spokes 180 degrees opposite to the section needing work are loosened and the the ones near the section needing work are tightened. First the spokes are loosened and then the ones needing work are tightened. This is done to avoid over stressing the opposing spokes.
In the truing process, first the axial run out is corrected and then the lateral run out is to be corrected. This is a job requiring much patience as it can take a long time to get done properly. Picture below shows the spokes and their corresponding actions:
Finally, after the wheel is no longer wobbling etc. all the spokes have to be tightened equally (1/4 turn at a time) starting from the valve and going round a full circle until an approximately equal amount of tightness can be felt. This activity is done two or three times. There is a special spoke torque wrench available, but I don't have it so I have relied on my experience and feel. I thought that this would disturb the wheel's level of trueness. Thankfully my fears were laid to rest when I rechecked the wheel. The write up on the web requires that I tap the spokes and listen to the ringing tone. If the spokes are equally tightened, they should sound the same. Similar principal of tuning a musical string instrument