Port Forwarding

I'm not very familiar with this kind of stuff and I need your help. What I want to be able to do is to host WarCraft III games. In order to do that, I think I have to open a port for WCIII or something. I'm sure I could figure that out, but the problem is that my dad forgot router username and password. The only way to recover them is to reset the router. If I do reset it, will I have to go about setting up the wireless and everything else again?