Resources can be attached to a Challenge while creating or editing a Challenge. You can add Resource Module, Collection or Group during challenge creation or editing.

Navigating to the Challenge through the Manage tab

Click on Manage button for the desired Challenge then click on Edit

Navigate to the Labs & Resources page by clicking on Labs & Resources on the bar

You can view resources in new tab by clicking "view in new tab" and add different Resource Module, Resource Collection and Resource Group by clicking add module , add collection and add group button respectively.

Attaching Resources while editing a Challenge

You can edit resources by adding resource from the left panel or can also remove resources from right panel using remove option in module, collection and group respectively according to the requirement in challenge edit page.