looking for the output of format as far as the disk with the root partition on it. we can make a better assessment with that.

however, you would have to back up /export/home. change start cylinder of /export/home (shrinking this), change cylinders for swap and then change the end cylinder for root (thus making it larger). save, label etc.

once out growfs /dev/rdsk/c1t1d0s0. newfs /export/home. restore /export/home

something to this effect.