If your application was written correctly in the first place then you would only have to make the change ONCE in yolur application!

One correct way of doing this properly the first time is to create a module with connection string in it and make it Public, then you could just call that module anywhere in your application!

By the sounds of it, you have done it this way or a similar way and you therefore have the connection string whenever you are making the connection to the Database.

So......you will have to make the change everywhere in your application!