Transact-SQL:
To pause a SQL Server database mirroring session, and to place the database in a SUSPENDED state using T-SQL, run this code from either database mirroring partner:
ALTER DATABASE [Database_Name] SET PARTNER SUSPEND
This will pause database mirroring and place the database in a SUSPENDED state:
SQL Server Management Studio:
To pause a SQL Server database mirroring session, and to place the database in a SUSPENDED state from SQL Server Management Studio:
Connect to the principal server instance -> Right-click the database -> select Tasks -> click Mirror:
Click 'Pause':
Click 'Yes' to confirm: