Grab the process designer section of the manual and if someone has gone on the core admin course or boot camp in your company, grab that manual too.
1. Deactivate the process
2. Double click the process to edit it
3. Open up the second tab at the bottom of the middle column called Toolbox if you hover over it and drag the blue action instance item onto your process
4. Choose the Reopen action.
5. Draw a line from the closed status to reopen and from reopen upto the Open status
6. Save process, activate, grant privs and jobsagood'en