if you have a device connected to the router either wirelessly or by ethernet then just type the router ip into chrome/ie/mozilla ie 192.168.0.1
then sign in (usually a standard password for sky router its u: admin p: sky) then under wireless you should see your password.
if you have a laptop connected by wireless you can also go to control panel> network sharing centre> click on connections> wirless properties>security>show password
