ok im really haevy handed so when im playing i tend to tense up and apply lots of preesure to the fret making it difficult to switch quickly, how do i stop this?
loosen up and just practice chord changes
First of all you should concentrate to use only the pressure reuqired to change the pitch by fretting a fret. Just try different body and guitar positions until you find the most comfortable for you. And always try to make your hands "fly" over the fretboard, not to crawl on it. You fingers that are not fretting should be at best relaxed with minimum tension.