Convert Recursive Function To Looped

I have a small class containing a recursive function (approximately 35 lines of code) written in VB.NET that I need converted into a looped function. It's important that the winning bidder have a solid understanding how to optimize speed and performance while maintaining the integrity and structure of the original class and function. This should take an experienced programmer less than half an hour to do. I'll show the code to top candidates so they can better understand what is needed.