Here are a few more examples of the chord changing rules.
G & D7.
With the G and D7 chords, the third finger on the 1st string for the G chord, moves from the 3rd fret to the 2nd fret into the D7 chord and then back again.
This is known as a guide finger.
Treat these two chords in the same manner as the prior chords with each exercise that was applied to the C & G7, but is now applied with the G & D7 chord.
The lower two notes on each chord are made with the 1st and 2nd fingers. They make a shape on the G chord and also with the D7 chord. This is called a Finger Relationship
D and A7 have a smiliar Finger Relationship. Fingers 1 & 2 of the D chord each move over a string for making the A7 chord. The 3rd finger of the D chord is released and put back down when the change comes back to the D chord.