Change everytime lastitems occurs into bestsellers, do NOT forget the info file
So when you install them, both last items and bestsellers get installed
Last items is a rather smal set of files so it is easy to do by hand, with larger amounts of files I usually use dreamweavers find and replace (case sensitive) to replace all instances of the modulenam and directory...
Search for last_items and LAST_ITEMS
With acts like these you can for instance even change 'bakery' into something called 'shop'