I'd configure it as WAP. I see no reason to use any other method even if this has no wifi. I'd use the same instructions.
Google this -> How to configure a router as a WAP.
I have an old Dlink DI-604 that I'd like to configure to work as a switch. I think this is possible but not sure how to do it. Switches are cheap but if I could save a few bucks with some tweaking I'd prefer that. Plus I figure I'd learn a bit about networking.