create a folder with a name of your choosing in the “C:\Program Files (x86)\Steam\skins” directory. Lets call it age2Overlay .
copy the entire \resource folder from “C:\Program Files (x86)\Steam\resource” to “C:\Program Files (x86)\Steam\skins\age2Overlay”
delete all folders except ‘style’ in “C:\Program Files (x86)\Steam\skins\age2Overlay\resource”.
Open the style folder in your custom skin folder.
Edit the file gameoverlay.styles (find “BottomRight” with ctrl+f), replace instances of BottomRight with TopRight. Make sure you have diplo/esc/etc menus hotkeyed.
Do the same thing for the file steam.styles . You can tweak some more settings here. These are my settings:
Notifications.PanelPosition "TopRight" // Can be "BottomRight", "BottomLeft", "TopRight", "TopLeft"
Notifications.PanelPosition "TopRight" [$OSX] // the dock is on the bottom for OSX, so instead pop top right like other apps do
Notifications.SlideDirection "None" // Can be "Vertical", "Horizontal", "None" and controls slide effect
Notifications.FadeInTime "0.1" // Controls the time it takes to slide/fade into view
Notifications.FadeOutTime "0.1" // Controls the time it takes to slide/fade out of view
Notifications.DisplayTime "6.5" // Controls the length of time at steady state after fade in and before fade out
Notifications.StackSize "1" // Controls how many panels we will stack before background queuing
Save the changes to both files.
Select the skin you made from Steam’s Settings > Interface : Select the skin… (your skin name, f.e. age2Overlay)