Dear compvis,
"Copying Cutechat.mdf and CuteChat.log", this step is incorrect, you don't need copy these two files, you can execute sql script against your database directly.
<add key="ConnectionString" value="server=(local);database=Cutechat;uid=sa;pwd=abcd123456"/>, this line is database connection string, please change "server=(local)" to "server=yourip".
"CuteChat" is database name, please change it to your actual database name.
uid is the username who has permission to access the database.
pwd is the password of that user.
If you need further help, please let me know.
Thank you for asking