Okay, I had a look at the theme and it's widgets. The widgets are customized to the theme, so I think your question is valid enough, and it seems their support doesn't help with customization questions even if you bought the theme, so here goes:
You can edit the php-file directly in thevoux-wp\inc\widgets\subscribe.php
.
Look at line 35:
<div class="small-3 columns"><button type="submit" name="submit" class="btn black"><?php _e("GO",'thevoux'); ?></button></div>
The _e() function is wordpress's way to translate strings, but I'll go the easy route, just remove it:
<div class="small-3 columns"><button type="submit" name="submit" class="btn black">OK</button></div>
Done! Keep in mind this "fix" has the potential to reset to its initial state if you update the theme.
As for the placeholder:
Same file, line 34:
<div class="small-9 columns"><input placeholder="<?php _e("Your E-Mail",'thevoux'); ?>" type="text" name="widget_subscribe" class="widget_subscribe"></div>
I think you can see where this is going...
<div class="small-9 columns"><input placeholder="E-Mail" type="text" name="widget_subscribe" class="widget_subscribe"></div>
And in an attempt to be thorough...
Editing the theme source files is not considered to be very pretty, especially since it can break on theme-updates. I would consider the proper fix to be:
- Unregister the widget.
- Extend the widget
- override the widget-function (Copy the old one, make changes).
- Re-register your "sparkling new" widget.
It's not hard if you know your way around Wordpress/PHP, but with the questions you are asking I probably wouldn't bother unless you are in it for the kicks.