Untangling a wig is patience work. If you pull from the top down, you tighten every knot below it. Start at the ends, work in sections, and let the wig tell you how fast you can go.
Set the wig up
Place it on a stand or hold it firmly at the cap. Lightly mist with water or wig detangler. For human hair, a small amount of leave-in conditioner can help. For synthetic hair, use products made for synthetic fibers.
Work in small sections
Clip the upper layers away. Comb the bottom inch first, then move upward slowly. A wide-tooth comb or flexible detangling brush is safer than a fine comb.
Nape tangles are normal
The nape rubs against collars and scarves, so it tangles first. Brush that area during wear instead of waiting until it becomes a mat.
Bottom line
To untangle a wig, mist, section, start at the ends, and work upward. Force is what ruins wigs.