Code cleanup methods and/or code coverage tools

Question

I have an application at work, which I started work on about 7 years ago. This was my first engagement in ASP.NET web applications, and coming from a Win32 background I had a hard time adjusting.

All this time, both the project and myself have "matured" and now most parts of it are well defined, properly structured and readable. However, there is a significant piece of it, that is "old junk". By that I mean old obsolete code, that was not working well, or was not properly structured, which has been replaced, but left in the source files instead of being removed. I must note here, that I was not the sole developer, but did most of the coding throughout.

What I want to do, is whenever I have free time at work, to remove the old obsolete and unused code. Are there any techniques/methodologies that I can use/follow in order to do this more efficiently? Any tools perhaps?

EDIT: (clarification based on feedback) The code I am talking about is not used anywhere, and is not called from anywhere in the project. What I need is way to find out where the code resides, since we are talking about a large codebase. So something in terms of code coverage tools would help. Any suggestions for asp.net projects? (the particular case is in Web Site project form)