I have kind of been put in charge of software development in one department of the company I work at. Only myself and a developer in the IT department have ever done programming as our main jobs and follow formal processes. The issue I am having is I don't know how to approach some co-workers assisting me part time with programming to tell them the code they wrote needs major refactoring. Just after a short review there are hundreds of lines of duplicated code and code that is duplicating features built into the framework etc. I just hate conflict and don't know how to tell them we have a lot of work to do. Any advice?