The web site password is set using the RDS Management HUD. Find and right-click the RDS Management HUD in your Personal Inventory then choose "Wear". The HUD will automatically attach in the Bottom HUD location (bottom center of your Viewer screen), although you may choose to attach it to any other HUD attachment point you wish. The HUD faceplate will appear similar to that shown on the right.
Click ("Touch") the center Set Pswd section then enter your desired password in the Text Box prompt that appears. The Text Box usually appears in the top-right corner of the Viewer window unless you have configured yours to display it in a different location. After you enter the password, click the Submit button to send your password to the web site.