[jsmartonly]

* Rewrite.

* NEVER modify existing one. Once you change one line of comment, you own all the code and problem from that point.

* If rewrite is not allowed, then ask huge pay raise for this work. Basically it is not about money, it is about bring everyone on the same page on the status of he existing solution.

* If the above does not work out, prepare to switch to another project, or quit the job totally.

[thaumaturgy]

There is absolutely no way to rewrite a million lines of business logic without ending up with an even bigger mess. See also: http://www.joelonsoftware.com/articles/fog0000000069.html

[jsmartonly]

I read that article before and totally agree with the point.

But that situation is different from the one we discuss here.

I do not know more information about ohmygord's project, but I basically want to point out to consider non-technical side of it. For example, people in the same team may not technical, and/or think maintaining existing solution is simple. I was in similar situation before, I was lucky to happen to select right strategy to deal with the situation.