How to cobrand WLID sign in page?

Assume using RPS6.0 http module, there is the steps.

Steps:
1. Add string IDs in Login UI section in MSM;
2. Add localized strings for each ID and each locale in Localization section in MSM;
3. Set propbag to load these cobranding strings:

LiveIdentity LiveID = HttpContext.Current.User.Identity as LiveIdentity;
Microsoft.Passport.RPS.RPSPropBag authPropBag = LiveID.CreateNewRPSPropBag();
authPropBag["WLContext"] = "mytitle$mysubtitle$myimage$myupselltext1$myupselltext2$myupselllearnmorelink";
WLIDSignInOutLiteral.Text = LiveID.GetTextTag("mysite", "nexus.passport-int.com/public/partner/rpsnetwork4.xml", authPropBag);