Change database association to new site collection

I have an existing site collection, eg: http://intranet/sitecollectionOLD associated with a database5.

I've created a new site collection, http://intranet/sitecollectionNEW.

I want to remove the association from http://intranet/sitecollectionOLD with database5, and associate that database withhttp://intranet/sitecollectionNEW

Thanks,

Scott