InfoPath Dev

we had to add a dll and the form is not accessible.  What are the steps to use the old SharePoint library as a secondary data source?  

I created an InfoPath form that collected employee information such as work experience and education, is there a way to pull that information into a new form so that the employees don’t have to re-type all of that again?  The current forms are being stored on SharePoint and the old InfoPath form is corrupt so I have to make a new form. ...