You'll need to buy a push pull pot and if you're dimarzio's don't have 4 conductor wiring you will need to get new pickups too. Then just use google or something for a wiring diagram. Probably could get one from Dimarzio or SD or wherever the pickups or pots are sold.
Quote by Usernames sucks
So my guitar has 3-way switch, 2 humbuckers, 1 vol and 1 tone. I have dimarzio pickups. I want to install a push pull volume knob, so if i pull it up i get single coil sound. What shuld i do?

Take it to a guitar shop?