Antrax88

Ok last night I was working on a config from a addon pack made by vilas. Its for personal use it is called russian armor pack. All I did was change the sides from 0(opfor) to 1(bluefor) or 2(independent) I wanted the cdf and napa to have a variety of tankz . Well I saved it and packed it but it ended up as. Bak file? How do I convert it as a pbo.?