The answer to 'how to clean replacement' is to regularly clean or replace your HVAC air filters. Air filters should be checked and cleaned or replaced every 1-3 months, depending on usage and indoor air quality. Dirty filters can reduce airflow, increase energy costs, and even damage your HVAC system.
To clean replacement filters, start by turning off power to your HVAC system. Remove the filter and gently vacuum or brush off any visible dirt and debris. You can also rinse the filter with clean water, but make sure it is completely dry before reinstalling. If the filter is damaged or very dirty, it's best to replace it entirely.