C# use a method on another form

On my main form in my Windows C# application I have this method:

        public void uploadNew(String newName, String filePath)
    {
        //Make sure file doesn't exist, then continue
        if (!File.Exists(basePath + POnumber + newName))
        {
            File.Copy(filePath, basePath + POnumber + newName);
            LogSubmit("Added New File " + newName);
            listFiles();
        }
        else
        {
            //The file already exists
                        }
    }

The meaning of the code really doesn't matter. Here's what I am trying to do. I needed a new form for a file upload form with some options and such. What I need is to send two variables back to the main form to plug into that method.

The operation is essentially this.

Main form -> Click button -> Form 2 -> operations -> Send back variables to uploadNew -> Close Form 2