Now that we've got the basic physical motions established let's try changing positions in time. You should count 1, 2, 3, 4, slowly and evenly. Strum the A major barre chord on 1, then while you are counting 2, 3, and 4, slide down two frets to the G major barre chord. Play the G major barre chord when your counting arrives at the 1.

Keep counting!

This time as you are counting 2, 3, and 4 slide back up two frets to the A major barre chord. When your count gets to 1 again, play the A major. Next try going up two frets to the B major barre chord.

The next step is to try changing to more distance fret amounts. In the video lesson I show examples of and suggest doing the follow changes:

Distance of Two Frets

A major down to G major, back up to A major, repeat.

A major up to B major, back down to A major, repeat.

Distance of Three Frets

A major down to F-sharp major, back up to A major, repeat.

A major up to C major, back down to A major, repeat.

Distance of Four Frets

A major down to F major, back up to A major, repeat.

A major up to C-sharp major, back down to A major, repeat.

You can and should continue this process as much as you need to in order to become proficient at barre chord changes.