Many organizations have workflows with e-mails or that make updates to a record that sometimes need to be changed. Microsoft CRM does not allow you to make changes to a workflow you don't own. However, that doesn't mean you can't update the workflow, you will simply need to reassign ownership to yourself before doing so.
Reassign Ownership From the Process List
You can select more than one workflow at once or a single workflow with this method.
*Important to note if selecting multiple workflows, reassignment deactivates a workflow so if you are reassigning more than one make sure to activate any that need to be active even if you don't get to editing right away.
Select the workflow(s) you wish to reassign and click the Reassign Icon in the toolbar.
In the pop up select assign to me or assign to another user and click assign.
Once the process is complete the workflow will be deactivated and the new assignee will be able to edit the workflow.
Reassign Ownership from the Workflow (Process) Record
If you are looking at a workflow and realize a change needs to be made you can reassign it to yourself or someone else from within the process record.