How to override the view.php of already created custom widget that does not extend or override view.

Summary

We have a custom widget which uses the ootb view.php, but I want to change the view, but am not able to override it

Content

My company created a custom OkcsSimpleSearch-widget.
The info.yml file looks like to use all OOTB-files (logic.js, controller.php, css and view.php), but in fact it does not. 
It does use it's own custom logic.js and controller.php.
But changes to the custom view.php do not have effect.

I changed the info.yml file but without success. I get a error* when loading the page and my search is not actived when I hit enter.