Kaneko-Suzuki developed epistemic logics of shallow depths with
multiple players for investigations of game theoretical problems. By
shallow depth, we mean that nested occurrences of belief operators of
players in formulae are restricted, typically to be of finite depths,
by a given epistemic structure. In this paper, we develop
various methods of surgical operations (cut and paste) of epistemic
world models. An example is a bouquet-making, i.e., tying several
models into a bouquet. Another example is to engraft a model to some
branches of another model. By these methods, we obtain various
meta-theorems on semantics and syntax on epistemic logics. To
illustrate possible uses of our meta-theorems, we present one game
theoretical theorem, which is also a meta-theorem in the sense of
logic.