There is usually a pdf file included with expansion pack that outlines installation steps:
- In the Solution Explorer window, right click the PurchasedControls folder
- Select Add->Existing Item
- Browse to the folder where you unzipped the expansion pack controls
- Select all of the files by clicking on the first, then holding down Shift and clicking on the last
- Click the Add button
- Build the project (Ctrl+Shift+B)