You can do that on your own.

Make sure the engine has been off for a few hours so as to avoid dealing with 2nd degree burns.

1. Get a 3-4 liter container and put it under your radiator drain.
2. Unscrew (its a plastic wingnut) the plug which is normally situated on the lower tank of the radiator.
3. Drain.
4. Tighten the plug.

Make sure you dispose of the liquid in a proper sewer drain not on the ground.

Now before you fill up your system again.
1. Get a radiator flush and fill it in
2. Add water.
3. Run your engine, intermittently revving to circulate and turbulate the detergent. Idling for about 15-30 minutes as necessary depending on the residue from the initial flush.
4. Drain the engine as per the procedure above.

Rinse and repeat as necessary so you can get as much corrosion out as possible.

Personally I would put a mesh during flushing on the radiator inlet to catch any loose debris.

Fill up your cooling loop with 30% coolant and the rest with clean preferably filtered water.

I recommend blowing air through your radiator core to dislodge dust and debris.

Wouldn't hurt to shampoo to degrease it and rinse with low pressure hose your thumb on the hose should work fine. Dry with pressurized air or just let it dry on its own.