Wireless Repeating Function (WDS) with 5031NV model

I recently up graded to u-verse internet, and for some reason I can't find a user manual for the att 5031NV model. Anyways, I am trying to add a third party wireless router as a repeater to the 5031NV model, and I don't see the configurations to do this. How can I add a wireless repeater to the 5031NV model?

Thank you,