What it is the correct way to remove a failed and suspended datbase from a DAG ?

Hi
we have a hard drive issue .can t read or open the folder where one database resides, therefore we had to failover this database .
Now we moved all mailboxes from this database, it is empty and we are ready to delete that mailbox .
What it is the best way to delete it ? will we be able to remove it even it is failed and suspended? and then can we remove the active one as it is empty now...
Thanks.
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