If you really have written the same code many times, you might be able to get away with a search-and-replace approach, and with a little luck everything you break will get caught by a compiler. But the more different ways you wrote it, the more likely you are to make things worse.
Learning a refactoring toolkit might be a fun project, but it may well take more than just a few hours. Code-that-writes-code is pretty tricky.
As you say, the alternative is also risky. So getting it right may be worth the effort. But in a lot of cases, it will be quite a bit of effort.
There's also the angle of keeping your eye in with other languages, e.g learning or keeping your python skills up to date if you need to do a quick bit of scripting to automate a task (and you don't usually use python).