How do I drain the radiator in a dodge caliber?

Replace the radiator as it is leaking internally. Remove and service the transmission as water in the transmission will destroy the bearings and clutches.
The best option if it has been leaking for a while is look for another vehicle ... possibly a cheaper option.

check and test fans and coolant sensor

It depends on what is wrong with it? Can you take the radiator to a radiator shop? If they can't fix it, get a new radiator. Just my opinion.
If you want to know how to remove radiator, we may be able to help you with that?

2007 Dodge Caliber Service Repair Manual And Dodge Caliber Body Repair... I was just scrolling past for answer to your problem and found this, looks good tho

There may be dirt blocking it. Let it rinse out for a while, check the looks of the fluid. Wiggle the plug while it drains. You may not have to remove it completely to drain.

drain coolant disconect radiator hoses remove cooling fans remove fasteners holding condenser to radiator position condenser away fron radiator remove radiator by lifting up be careful not to dammage cooling coils

TYou will have to put the vehicle up un ramps, because the fan assembly must be removed from the bottom rather than the top of the radiator. The Caliber has an electric cooling fan which, which must be disconnected electrically before removal. Then remove the fan shroud from the radiator. Drain the radiator by removing the lower radiator hose (you may be able to reuse this coolant later). The remove the upper radiator hose and the tube going to the coolant recovery tank. Unbolt the radiator's mounting bolts , and either lift the radiator out or (if there isn't enough clearance to lift it) lower it out the same way as the fan. Install the new radiator by reversing the process. Good luck.

Many radiators no longer have a "drain plug". Using the drain plug can cause the plug to leak after draining. The best option if you wish to drain the radiator is to pull the lower hose.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Check the factory stickers under the hood or on the radiator support, sometimes they show it.

Not sure,but look on drivers side below radiator.