The first step in unlearning X is to avoid it. Try to avoid speaking and hearing it. Learning X involves using and interacting with it frequently, so you must do the opposite.
Forgetting [INSERT LANGUAGE]
Step 2 - Whack Your Head
If you don't remember anything, you won't remember X. If all else fails, proceed to Step 3.
Forgetting [INSERT LANGUAGE]
Step 3 - Healthy Lifestyle!
Having a healthy diet, getting enough sleep, and doing enough physical activity such as yoga may prevent you from remembering unpleasant things such as X.