modify a joomla plugin - repost 2

We need a simple modification to a joomla plugin. the plugin is called Guru from this website [login to view URL] what we need is that once the user has taken the test of this final exam within the plugin, a must is that he only sees the results page once when he finishes the exam. Currently the user can log into his account and see the exam that he has took and see the whole questions that he failed on, we need this to be removed or stopped the user from seeing this within his account environment. should be only a slight code change or removal, Please advise and i will pm the website so that you can understand better, the project is no more than a $30 budget