A call to `helm-switch-major-mode' will give you a `helm' selection of all available major modes. Selecting a target will activate the major mode. The persistent action is to show help about the selected major mode. A call to `helm-enable-minor-mode' will give you a `helm' selection of all available minor modes. Selecting a target will activate the minor mode. The persistent action is to show help about the selected minor mode. A call to `helm-disable-minor-mode' will give you a `helm' selection of active minor modes. Selecting a target will deactivate the minor mode. The persistent action is to show help about the selected minor mode.