When you decide to change the default Joomla! template on a production site, it is a usual process to edit each module individually and change its position, as rarely any two template have same positions in similar locations - 'user1' position on one template can be 'user4' position in the new template; that's when Easy Module Changer is useful.

Easy Module Changer is a mass module changing backend extension that changes the position of modules in bulk. An ideal tool if you want to change say all modules on position 'left' to position 'right', EMC is very useful when you change the default template and want to quickly change the module positions.