Improve mileage - DPF removal

[captainmike]

We, my friend and I, would like to improve mileage. My friend has an '07 Duramax. What is involved in removing the DPF and modifying the appropriate software? (For off -road use of course) How much lmprovment can we expect and how much will the mod cost? The Duramax is currently getting about 14 mpg average. Any help will be most appreciated.

Thanks, Mike in Fla.