OMG its pretty simple to do especially with filebox and leafpad installed. In short
1. Get filebox and leafpad
2. Enable root access in Filebox from its setting, select leafpad as text editor
3. Browse to /etc/systemui
4. Long press file>Copy it>Paste it somewhere as backup
5. Long press file>Edit
6. Move comment indicator(<!--) few line below so that reboot option comes out of comment. Save changes
7. done! killall systemui or reboot to apply changes.

Anyways, great job to post the trick.