Always back up your original data if you have it. Downloading firmware from unofficial sources carries a risk of "bricking" your head unit if the files are incorrect for your specific model. Ensure the repack is specifically for the and not the NSCP-W61 or NSZT models, as the firmware is not interchangeable.
Open the screen panel and insert the card into the slot (not the music/media slot). nsddw61 sd card repack
Some repacks attempt to enable basic English menus, though full English conversion for this model is notoriously difficult. Why Do You Need a Repack? Most users search for a repack for one of three reasons: Always back up your original data if you have it