To uninstall the DNN module is actually quite complex via code. There are couple of table modules related and depends on each other. Fortunately, the DNN framework has a built in delete method for these modules. There are 3 tables in the database that are related to the module definitions. They are: DesktopModules, ModuleDefinitions and PortalDesktopModules. The DesktopModules and ModuleDefinitions tables are global tables that are linked to all portals. While PortalDesktopModules table contains a relationship between each portals and what modules can be used by each individual portal.

Lets say you want to remove a list of modules containing a name started with MyModule_.

/* Firstly, you need to include these namespaces on the top of the code */
/* This namespace for Dictionary collection */
using System.Collections;
/* These namespaces for module collection */
using DotNetNuke.Entities.Modules;
using DotNetNuke.Entities.Modules.Definitions;

The next part is to grab a list of module definitions collection and compare if the name contains MyModule_

/* Declare ModuleDefinitionController object */
ModuleDefinitionController objModuleDefinitionController = new ModuleDefinitionController();

/* Declare DesktopModuleController object */
DesktopModuleController objDesktopModuleController = new DesktopModuleController();

/* Get dictionary module collection */
Dictionary<int, ModuleDefinitionInfo>  moduleList = ModuleDefinitionController.GetModuleDefinitions();

/* Perform a looping in the module list */
foreach (int i in moduleList.Keys) {
	/* We only delete the module friendly name contains MyModule_ */
	if (moduleList[i].FriendlyName.IndexOf("MyModule_") >= 0) {
		/* Delete the module from table module definitions */
		objModuleDefinitionController.DeleteModuleDefinition(moduleList[i].ModuleDefID);

		/* Delete the module from table desktop modules */
		objDesktopModuleController.DeleteDesktopModule(moduleList[i].DesktopModuleID);

		/* Delete the module from portal desktop modules */
		DesktopModuleController.RemoveDesktopModuleFromPortal(PortalId, moduleList[i].DesktopModuleID, true);
	}
}