How can I remove my Skype Name from the sign-in screen in Skype for Mac OS X?
When you sign in to Skype, your Skype Name is added to the drop-down list in the sign-in screen.
To remove your Skype Name from the sign-in screen:
In the menu bar, click Go > Go To Folder….
Type ~/Library/Application Support/Skype into the dialog box that appears and click Go.
Important: Make sure that you include the ~ sign at the beginning of the path as it indicates the user folder. Using the path without this sign will take you to the general system folder that doesn’t include the Skype folder.
Find the folder named after the Skype Name you wish to remove from the Skype sign-in screen, and move it to trash.
When you restart Skype, your Skype Name will no longer be displayed.