Unfortunately, you can't move this label.
The browser decides how it's rendered.
However, there are some options.
For example, you can make the input's label to be of the same color as your background, like this:
<input type="file" class="remove-label">
And css:
input.remove-label
{
color: #fff;
}
OR give this input a small width, so only a button will be displayed.
And then just place your custom label in a div where you'd like it to be.
But this obviously won't let the user see a 'current' file.