How to Delete "distribution" replication database

I was having a problem to delete distribution database created by replication, I was unable to remove this database even i removed all configurations related to replication.

Then after some research i got this way to delete it. First take if offline and then delete it.

USE MASTER

GO

ALTER DATABASE distribution SET OFFLINE;

DROP DATABASE distribution;

Then delete physical files .ldf and .mdf from the disk manually.