How do I remove a cancelled SKU from all orders?

Use the Cancel Style function to completely remove the SKU from all customer orders. The system will report which order contains the SKU. Inventory > Cancel Style

Use the Substitute SKU function to replace the cancelled SKU with another. Advanced > Utilities > Substitute SKUs
Click here for Detailed Instructions

If you wish to keep the SKU in the system catalog, and only remove it from the orders, Advanced > Utilities >Remove a SKU from all Unreleased Orders > Enter the SKU > GO. In this case, you may want to mark the SKU as "Stop Selling". 

Please note that none of the listed functions affect purchase orders.