You'll want to follow the Unix instructions.
To set permissions w/ WS_FTP, you highlight the file(s)/folder(s) you want to change, right-click, then choose chmod (Unix) from the menu.
The 3 numbers (e.g., 755) correspond with Owner/Group/Other. 7 means you check all 3 boxes (RWX) under "Owner". 5 means you check off Read and Execute (R-X). So, 777 would mean to check all the boxes. If that's too confusing, let me know... lol