Poi,. You can use a wrench to remove the S pipe. Make sure you shut the water off, and have a bucket ready for the water that might be in the pipe. Aloha!
Since it's a drain, you DO NOT have to turn your water off. Put a bucket under the P trap. Then loosen the nuts and pull the P trap out over the bucket. Assuming it's plugged, take it outside and and blow the plug out with your garden hose. If it's not possible to take it outside, then hold it over the bucket and use a wire hanger to push the plug out. Rinse it out and replace it the same way you took it off. Hand-tighten only.