How can I change Category Icons in next revo themes

I have next revo themes. I need to change my category icons. I can see help section eexplain how to change category icons… but i dnt khow how… can you help me with step by step

Create a image with 60x60 resolution and rename it to “category_id.png”, where category_id is a numeric id of your desired category. Upload all images to your theme’s image folder, that’s what I understand from above screenshot.