How to have application use different databases via wcf dataservice

How to have application use different databases via wcf dataservice

We are building a application that will be sold to clients, the SQL Server
database will be hosted by us. We will have a database for each client. We
are not sure if we can use one WCF data service to access the different
databases. Using Entity Framework to build the database.
How can I accomplish this so the client can pass in the correct database
name or connection string?
This Different databases using WCF dataservice said it is possible, but
doesn't really get into specifics.
This WCF Service for Multiple clients with database(each for client) looks
to be the same question, but has no answers.