Webzash on CakePHP

I have a working CakePHP (2.5.6) project having Webzash (accounting software) installed and running as a plugin.

Now I want to add a new type of report in that Webzash but I am just unable to even edit the existing reports in the Webzash.

Does anyone know how to add/edit a plugin running on CakePHP ? Or is Webzash even editable ?!

I have been reading the Cookbook (2.x) and looking for solutions online but to no avail so here I am with my first ever question.

Any help would be highly appreciated !