We consider a generalization of heterogeneous meta-programs by (1) introducing an extra level of abstraction within the meta-program structure, and (2) meta-program transformations. We define basic terms, formalize transformation tasks, consider properties of meta-program transformations and rules to manage complexity through the following transformation processes: (1) reverse transformation, when a correct one-stage meta-program M¹ is transformed into the equivalent two-stage meta-meta-program M²; (2) two-stage forward transformations, when M² is transformed into a set of meta-programs, and each meta-program is transformed into a set of target programs. The results are as follows: (a) formalization of the transformation processes within the heterogeneous meta-programming paradigm; (b) introduction and approval of equivalent transformations of meta-programs into meta-meta-programs and vice versa; (c) introduction of metrics to evaluate complexity of meta-specifications. The results are approved by examples, theoretical reasoning and experiments.