If I remember correctly, there are 3 PTO positions. The forward one is just front PTO, the middle one is front and rear PTO, and the rear one is just rear PTO and that is the one that allows you to operate the rear PTO without being on the tractor seat.
Here's what my manual says:
Testing Rear PTO/Park Brake Interface
1. Sit on the operator’s seat.
2. Lock the park brake.
3. Push the PTO switch knob to the disengaged/off position.
4. Move the transmission range shift lever to the N (neutral) position.
5. Start the engine.
6. Move the PTO selector lever to the rear PTO only position.
7. Raise up from the operator’s seat. Do not dismount the machine.
8. Pull the PTO switch knob to the engaged/on position.
• The rear PTO should operate.
9. Sit on the operator’s seat.
10. Unlock the park brake.
11. Raise up from the operator’s seat. Do not dismount the machine.
• The engine must stop.
12. Push the PTO switch knob to the disengaged/off position.
13. Turn the key switch to the OFF position.
Danny