Go to Resource Planner > Find the class
Click on the class > Click on the "pen and paper" icon
Click on "Base information"
Click on "Change" next to the product
Select the new product from the roll down list. It is possible to filter on product label here
If the product you wish to switch to is not in the list, it is because the product doesn't have the already booked resources added to its resource requirements. Read about how to add resource reqiurements to a group acitivity product in the article below
Click on "Complete"
Click on "OK"
