This tutorial discusses the difference between Replace and Exchange Selected. It then goes on to show how these functions can be used, in an architectural setting, where instance elements need to precisely and accurately repeat across an angle. Other functions used in this tutorial which are used as part of the workflow include Scale, Flip Perpendicular to Grid, Lock Position and ReCenter Origin, and 2-click Custom Active Grid creation. There is some really cool functionality demonstrated in this tutorial so make sure and watch all the way through.