How do I remove a code mapping from a model?

I used the code mapping editor and api to add code mappings to several models. This appears to have caused issues with other members of the team that do not have the embeded coder toolbox (see this question). I would like to set it up where I configure the code mappings later, as part of the code generation process, instead of just having it on all the time. But I cannot figure out how to remove code mappings from a model that has them. Nothing in the GUI shows how to do it, and the code.mapping command line path has no remove functions.