If you can sucessfully make a barr chord of any type, congratulations. I've been playing nearly 25 years and I remember how tuff barr chords were. But stay with it. If the action on your strings is set high (as it might be on an acoustic guitar) it will be more difficult. Try moving to the A position when making your chord. A 'minor chord' lowers the 3rd of the scale. In a typical barr chord the 3rd is played using the greatest finger. Simply lift it from touching any string and your first finger "barr" will hit the correct fret causing the minor sound. NOTE: it is easier to learn playing in the middle of the guitar neck than at either extreme end...
good luck :)