A minor chord is based on the same triad as its major chord counter part. The only difference is the third degree is flatted. The note formula for the minor is thus root note, flatted third degree and fifth degree of the scale.
So, you just move back the third degree a half step or one fret and, there you have it. These chords are, of course, movable. Here are the A minor, D minor and E minor versions:
Note that these are movable. But as I mentioned before in Part 1, you can take advantage of the open strings. The 5th (or A) string is the base note for the Am chord. The 4th (or D) string is the base note for the Dm chord. And the 6th (or E) string is the base note for the Em chord.