Simple Change to Visual Basic Program

I have an application written in Visual Basic.
I require a very small modification to the program.
Currently the project compiles in VS2017.
I want to remain using VS2017. I do not want the hassle of
installing another version of Visual Studio.

Requirements:
The program sends a hex (text) file to the serial port in
the menu command with a dialog window.

I need the program to send the file when the command button is
pressed without the dialog window. The file must be present
in the current directory where the application resides.
If the file is not present, inform the user with an error message.

The file to be sent is listed in the text box directly
under each of the three command buttons.
Please look at the attached picture.

(please leave the file menu as it is).

I am looking for a quick turnaround as I do not have a great deal
of time to spend on this project.