How to change icon on standalone file and on left corner of stack (defalut Renrev Icon) (Runre v.2.5.1)

[Supote-Gmail]

Dear Sir

    Now I use Runrev Version 2.5.1. I want to know how to change icon on 
standalone file and on left corner of stack (defalut Renrev Icon). 
Please help me. Urgent!!!!!!!
     Thank you very much

Best regards,
Supote