In the side bar just increase the number listed by scale. It's 1 by default on all objects, increase it to 1.1>1.2>1.3. Or decrease.
I have had crashing when doing this on occasion so save frequently and make backups.
Also you can set a random scale in the instance painter for plants and such.
Last edited by SniperHF; 03/12/14 09:19 PM.