The website you want to go to is this one. The other is good but this is more direct and to the point.
This is the link you want if you want to return to active duty. Select officers on the left then at the bottom select special flying programs. It will take you to one more site with several links. Choose "Voluntary Return to Active Duty". The whole process is right there on the website. Including everything you need to apply and get accepted. Good luck