Right now I have a Time Capsule for my primary router. I use an Airport Express (joined my network) to set-up Air Tunes and a printer. I would like to extend my wireless network range so I get a nice strong signal on the third floor (for my iPhone and iPad). My TC is in the basement where my modem is. Can I use an Airport Extreme to extend my TC network. If so, can someone provide some simple set-up instructions. I would like to keep my Airport Express for my Air Tunes and printer.