One of the shortcoming of current (meta-)modelling tools is their strong reliance on their implementation level.
While it does offer its benefits, certainly for tool developers, it seriously impedes portability of models.
Model management operations are handcoded in the implementation language of the tool, making it difficult for users to grasp their semantics.
Furthermore, model management operations themselves have strong reliance on the internal data structures used by the tool, making comparison of algorithms, even at a conceptual level, difficult.
In this paper, we analyze the reasons and effects for this strong reliance on the implementation level.
We offer a solution which allows the explicit modelling of model management operations in a strict metamodelling framework.
Even those operations that require access to multiple levels in the modelling hierarchy are supported.
To aid in this effort, we furthermore break the strong link between model management operations and the data structures in use by the (meta-)modelling tool.
Our technique is illustrated through the explicit modelling of a retyping operation on a petri net.
