How do I uninstall Gengo without breaking incoming links?

I use Gengo to manage translations in my blog since I started it, but the plugin is having compatibility issues for too long. I’m not blaming the developers, but I’m afraid I won’t be able to tolerate the “foreach” error message in my blog.

I’d like to uninstall Gengo, but I’m afraid there will be no more “en/” and “pt/” at the end of the permalinks, and that could severelly break the links I received from other sites, not to mentions search engines.

How do I uninstall/remove/disable and make the old incoming links land in the correct pages?