Ok, this is not done by driving a certain number of miles. Instead, it is done by following very specific monitor reset directions. Make sure to do them exactly as described and in the order they are given. The 3rd step in the procedure is what sets the evap system monitors to ready. The below procedure is the only GM procedure for this:
total time to perform is about 15 minutes. Again, and this is critical, it is not based upon how many miles you drive, but upon doing the above procedure in the exact order described.