You can upload your style assets by dragging it to Style Asset Box
Go to the Style you want to upload assets
Click Picture & Digital Asset box. You can click on PIN icon to make it easier to upload
Drag the file you want to upload to the Digital Asset Box
After Asset file upload, you can see it by double clicking it
Your Asset files will be stored in appropriate folder location
Go to My Computer > Open N41 Source network drive (usually Drive Z:\ or N:\)