A WebAppAccess of a linked model can be used to set or change the instantiated model that is associated with a linked model slot.
For example, you can instantiate a model and reassign the linked model using the new model, like so:
// create or get a singleton instance of model "C"
WebAppAccess modelC = webAppAccess.getModelInstance("C", null, true);
// Get the linked model slot holder
LinkedModel linkedModel = webAppAccess.getLinkedModel("LM1");
// Now set the instance on the linked model slot
Now when calls to LM1 are made they will go to the new model. This assumes that when you swap out linked models you replace them with models that contain the same methods/pages that may be called.
Parent topic: Linked models