1. Click Inventory > Item Search
2. Change the category to "gift" if its under gift packs. Search for the product.
3. Click the product
4. Click Assembly Tab
5. Under "Find Existing Assembly Part", type in the product you want to add. Make sure to add in the product without a hyphen. Tick the "items with inventory" box
6. Select the product to add into the box
7. If you want to change or edit the number of build, click Assembly tab and type in the number in the build how many box.