Mark a level line around the room at any point. Then measure from the ceiling to the line to determine the lowest point of the ceiling along all the walls. Mark this point's location.
Next, measure 12-1/4" down from the lowest point and transfer this measurement to the wall, snapping another chalk line. This will be the line that marks the top of the slat wall.
Determine the location of studs using a stud sensor and mark all stud placements.
Install the J-tracks at the end of the panels, then set the first panel level with the horizontal chalk line at the 12-1/4" measurement. Using screws long enough to go into the studs at least 1" deep to secure the panel at every slot along the stud line throughout the first row.
To start the second panel, align the tongue on the top of the second panel with the groove on the bottom of the first row. Drill a screw into every slot along the stud line. Continue process until all slatwall pieces are installed.