MCO to CBR and back
I assume you are taking the Mears Connect. It’s basically the same as Disney’s Magical Express – same location and process. Here are the instructions:
Here’s a map with a red X where the pickup is. The tricky thing is making sure you are on the Terminal B side, because the two sides look identical and are connected only on Level 3. Head to the 1st floor and walk to the end of the hall for checking. There is plenty of signage once you are down there.
For your return trip, check with the front desk at CBR. Usually Mears and other shuttle buses stop at the outer curb at the port cochere of each hotel. The front desk will give you special instructions. You should receive a boarding time in your email – just make sure you arrive when they tell you to and even a bit early (10-15 minutes) just in case.
Sometimes they arrive early and are already gone when you get there, or maybe there aren’t any buses available at your time. If so, the front desk will cover the cost of a taxi for you.
P.S. If you are on JetBlue or one of the other Terminal C airlines, the map I posted is not applicable.