Change & Migration of Publishable document

Can anybody pls let me know what are the neccesarry steps when we update an existing publishable (to Broker) document and migrate the changes from one to other environment (that document already exists in target environment)? I�m mainly concern to make this updated publishable document Synchronous with broker in all environments.
Also pls let me know if there are any differences when we migrate from non-clustered to non-clustered and non-clustered to clustered environments?
wM ver 6.1.
Broker Version 6.1.0.3.158 081105
Broker API Version 6.1SP1
Pls let me know if you need more information.

Thanks for your help!

Deep