First you need to have created your new SAP Portal theme or know which of the
existing themes within your SAP portal you are going to uw.
Step 1 - Login
First things first you need to login to your SAP portal as the Portal administrator with system administration rights
Step 2 - Create portal desktop
Once you have successfully saved your new theme or know the name of the existing one your going to use goto the 'Desktops & Display Rules' section. This is within the System Administration->Portal Displays tabs. Within the 'Portal Content' folder find the folder containing your content and right click on the 'Portal Users' folder within here. select New->Portal Desktop.
Step 3 - Portal desktop details
Now enter the Portal Desktop Name and ID
Step 4 - Portal desktop details
Now right click on the Framework page you are using(i.e. 'My Framework Page' the one you created) and select 'Add Framework Page to Portal Desktop'
This will now add the framework to your new Portal desktop
Step 5 - Add theme
Now goto the themes folder, still within 'Portal content' and select 'Add theme to Portal Desktop'. This will now add the theme to your new Portal desktop
Step 6 - Save and close
Now press the save button followed by the close button and your are done.
Step 7 - Next step
Next step is to assign your desktop to users, this can be to all users or specific user.