I have created a video walkthrough of implementing side-by-side versioning with a web-hosted xamlx workflow service here:
This project provides a demo of implementing side-by-side versioning with a web-hosted xamlx workflow service, as described in the accompanying MSDN topic Side by Side Versioning in WorkflowServiceHost.
The WorkflowServiceHost side-by-side versioning introduced in .NET Framework 4.5 provides the capability to host multiple versions of a workflow service on a single endpoint. The side-by-side functionality provided allows a workflow service to be configured so that new instances of the workflow service are created using the new workflow definition, while running instances complete using the existing definition. It is very easy to configure and implement, and this code gallery project provides a running sample and a video walkthrough that demonstrates how to do it.