A folder is created for each Skype account accessed on a computer. This folder contains all settings pertaining to the specific user. Remove a Skype profile from a computer if you no longer wish to use or have others use or access the account.
1. Click the 'Start' button
2. Click Run and type '%appdata%\skype' in the 'Run' box and press the "Enter" key. All files associated with your Skype program appear in the windows explorer.
3. Click the file of the name of the profile you wish to remove and press "Delete." Prior to this step, copy the pictures folder or any files that you need.
4.Launch Skype. The profile no longer appears in the Sign-In screen of Skype.
You can refer to the link: How to uninstall and re-install Skype .
When the installation is done, log in with your friend's Skype name.
Hope this helps.
Please reply if you have any further questions.
Thanks and Regards,