  We demonstrate that it is possible to use atomic manipulation techniques to
adiabatically tune between one-dimensional and two-dimensional topological
superconductors in magnet--superconductor hybrid (MSH) structures. This allows
one to change the nature of the associated Majorana fermions between localized
bound states and chiral Majorana edge modes, and provides a new approach for
counting the topological invariant of the system -- the Chern number -- in real
space. Moreover, we show that the topological nature of finite-size MSH
structures can be characterized using the Chern number density which
adiabatically connects MSH structures to macroscopic, translationally invariant
topological superconductors characterized by an integer Chern number. These
results open new possibilities for studying the nature of topological
superconductivity in MSH structures using atomic manipulation techniques.
