I have the option of taking advantage of a Manulife rehab work return. Has anyone had experience with this? What does it involve?
It is different for every person.
You and your doctor come up with a plan about what you think you can do (part time work, physio, etc).
Typically you will be assigned a rehabilitation consultant who will come up with a plan for a return to work. They often will send you to a physiotherapist and possibly a psychologist.
Most policies it is mandatory that you cooperate and participate.
If you feel that you can go back to work soon then this can be helpful. If it is unknown or unlikely that you will be able to return to work, then this can be a nightmare.
edit: Just recognized your other posts and situation. In your case I would try rehab and also apply for cpp retirement incase rehab is beyond your abilities.