Add Login and Signup for React.js APP -- 2

I got a node app made in react/express/redux. I need to add login and signup and authentication and analytics tracking and donation request to my app. This one freelancer used passport and added all this stuff. But he quit early and i got some css issues and other stuff needed done in Mongo DB. This is all on my development app. But u can fix it up and finish and deploy to production. Or you can start over with all this. Must start work now and finish ASAP. Must know React and Node and Express and Mongo and Server Side Isomorphic Javascript.