how to clean up unwanted database...

take a look at this link, hope this will help you

 

http://sqlmag.com/database-administration/clean-your-sql-server-databases 

- In sql server management studio SSMS when you right click on a table you can check dependencies. Then you can know if the table is related to any other table or is used in stored procedure.

 

- You can clean log and shrink database as well.

 

- Right click on database and you can check if any connections are active.

You can use DBCC Shrink database on the below link

https://msdn.microsoft.com/en-us/library/ms190488(v=sql.90).aspx  

 

 Check out the discussion in the below forum

http://dba.stackexchange.com/questions/28360/sql-server-database-size-didnt-decrease-after-deleting-large-number-of-rows

 

Hope this helps