How difficult is it to change the radiator?

Here is a generic guide with specific instructions in the diagrams below for your car.

https://www.2carpros.com/articles/how-to-replace-a-car-radiator

1.Remove air cleaner and duct assembly.
2.Drain the coolant.
3.Remove the engine strut brace bolts from the upper tie bar and rotate the strut(s) and brace(s) rearward.
Important: To prevent shearing of rubber bushing(s) loosen bolt(s) on engine strut(s) before swinging strut(s).

4.Remove the electric cooling fans.
5.Remove the upper radiator brackets and bolts.
6.Use the J 38185 in order to reposition the hose clamps at the radiator.
7.Disconnect the radiator inlet hose from the radiator.
8.Disconnect the radiator outlet hose from the radiator.

9.Remove the low coolant module.
10.Disconnect the transaxle oil cooler pipes from the radiator. Refer to one of the following:
†Automatic Transmission Oil Cooler Pipes Replacement (With Threaded Fittings) in Automatic Transaxle - 4T60-E
†Automatic Transmission Oil Cooler Pipes Replacement (With Quick Connect Fittings) in Automatic Transaxle - 4T60-E
†Automatic Transmission Oil Cooler Pipes Replacement (With Threaded Fittings) in Automatic Transaxle - 4T65-E.
†Automatic Transmission Oil Cooler Pipes Replacement (With Quick Connect Fittings) in Automatic Transaxle - 4T65-E.
11.Remove the radiator.

INSTALLATION PROCEDURE

1.Install the radiator to the lower mounts.
2.Connect the transaxle oil cooler lines to the radiator. Refer to one of the following:
†Automatic Transmission Oil Cooler Pipes Replacement (With Threaded Fittings) in Automatic Transaxle - 4T60-E
†Automatic Transmission Oil Cooler Pipes Replacement (With Quick Connect Fittings) in Automatic Transaxle - 4T60-E
†Automatic Transmission Oil Cooler Pipes Replacement (With Threaded Fittings) in Automatic Transaxle - 4T65-E.
†Automatic Transmission Oil Cooler Pipes Replacement (With Quick Connect Fittings) in Automatic Transaxle - 4T65-E.
3.Install the low coolant module.
4.Install the radiator outlet hose.
5.Install the radiator inlet hose.
6.Use the J 38185 in order to reposition and install the hose clamps at the radiator.

7.Install the radiator brackets and bolts.
†Tighten the bolts to 24 Nm (18 ft. lbs.)
Notice: Refer to Fastener Notice in Service Precautions.

8.Install the electric cooling fans.
9.Install the engine mount struts.
10.Fill the cooling system.
11.Install the air cleaner and the duct assembly.
12.Inspect for leaks.

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.