Changing from one chord shape to another can be very hard at first. You have to develop your muscle memory so that your fingers eventually know what they have to do without looking at them. You can, however, break the task into smaller parts. Try to also to think about what you are doing to help the learning process and reduce frustration. Looking for similarities between chords also helps. Read on to learn how.
You can sometimes use different fingerings for the same chord to make the change to the next chord easier.
example: when changing from E minor to E major, you want to use 2nd and 3rd finger for the minor, so that the first finger can fret the 1st fret on the G string. But, if the next chord is an Am, the change is easier if you use 1st and 2nd fingers for the E minor, because then you already have the 2nd finger ready for the A minor shape and you don't have to lift it at all.
VERTICALLY MOVABLE CHORD SHAPES
There are some shapes that you can move from one set of strings to another to get a different chord. The quality of the chord however changes.
example: E major-> A minor, fingers hold the same shape, but move from the 5th, 4th and 3rd string to 4th, 3rd and 2nd string. Similar: Esus4->A, A->Dmaj7, Amaj7->D7