Not too difficult but a little messy. It's easier to work through the wheel well.

Drain the engine coolant.

Remove the marmon clamp from the turbocharger exhaust outlet pipe. You can skip this step if you're careful when raising the engine.

Raise vehicle.

Raise engine enough to clear the mount.

Remove the oil filter.

Remove the engine block heater electrical connector.

Remove the two left engine mount to bracket bolts.

Remove the oil cooler front header retaining bolts.

Remove the oil cooler rear header retaining bolts.

Reposition the engine assembly using a suitable jack.

Remove the oil cooler and gaskets from vehicle.

Installation
Install the engine oil cooler, rear gasket and three rear bolts to snug.

Install the oil cooler front header gasket and two retaining bolts. Tighten bolts to 32 Nm (24 lb-ft).

Lower the engine in its original position.

Install two engine mount to bracket bolts, tighten bolts to standard torque.

Tighten the three oil cooler rear header retaining bolts to 19 Nm (14 lb-ft).

Install the oil filter.

Connect the engine block heater electrical connector.

Lower vehicle.

Refill the engine cooling system.

Refill the engine oil.