1. Click Products on Navigation bar and select PriceBooks from the drop-down

2. Click on the Pricebook for which the Products must be added

3. Scroll to the Products field, select the Product by searching it in Search Products and click Add to add the Product. ( Make sure that the product is already added in your account. Refer the following article to know: How To add a new Product? )

    Update the Product with Price and Discount 

    Click Save All to Save changes

Note: Products can be edited, added or removed from the list whenever required