将大型C＃winforms应用程序升级到WPF的最简单方法是什么？

I work on a large C# application (approximately 450,000 lines of code), we constantly have problems with desktop heap and GDI handle leaks. WPF solves these issues, but I don't know what is the best way to upgrade (I expect this is going to take a long time). The application has only a few forms but these can contain many different sets of user-controls which are determined programatically.I work on a large C# application (approximately