IF you booked CL, you can make the requests through the IPO. (The fabulous discount allowed us to book CL without dying over the price per night--I have already submitted my requests to the two IPOs at the two hotels we're staying at.)
If you didn't book CL, you can call Orbitz and ask them to call the requests into Disney. I'd offer to hold while the agent did so and cross your fingers they aren't sitting there and muting you and checking their FB page while you wait.
If CL doesn't pertain to you, I would also suggest you skip online check in and do a normal check in so you can make the request when you're at the desk.
Good luck!