The easiest way to move a Project between Workflows is to do so when you are creating the new Workflow. The newly created Workflow will "inherit" the Workflow of the Project, and once the Workflow is created, you can then customize your Workflow as needed.
More on this - Article: Creating and Editing Workflows.
If you have already created a Workflow and now want to move over a Project or even two or three, you can do so by navigating to Settings > Workflows and clicking on the Workflow that contains the Project you'd like to move.
Then you can click on the Project and select the Workflow you'd like to move it over to.
In the case that you want to move a Project to another Workflow that has a different Workflow, you can update Workflow 2's Workflow to match the Workflow of Workflow 1.