Restore database - maintenance plan task
There is no 'Restore DB Task' in the maintenance plan. You will have to use the Execute T-SQL Statement Task. In that task, add a restore script in your T-SQL statement. Simple example: 

RESTORE DATABASE YourDBName FROM DISK = 'D:\DBbackups\YourDB.BAK'
WITH REPLACE
GO


Then create a schedule for weekly execution. Hope this is what the business requires, as you are overwriting a DB.