Rainbow vacuum cleaners do not typically use HEPA filters. Instead, they utilize a unique water-based filtration system to trap dirt and debris.
However, if Rainbow has introduced a model that uses a HEPA filter , the specific process for changing the filter might vary depending on the model. The manual should have detailed instructions on how to replace the HEPA filter, including illustrations or diagrams to guide you through the process.
If you don't have the manual or cannot find it, you can visit the official Rainbow website or contact their customer support for assistance. They will be able to provide you with the correct information on how to change the HEPA filter for your particular model.