  We study numerically the so-called ``turn-over scenario'' for rotating
magnetic white dwarfs and neutron stars. According to this scenario, the
magnetic symmetry axis of the model inclines at a gradually increasing angle
(the so-called ``turn-over angle'') relative to the invariant angular momentum
axis. Consequently, the model becomes ``perpendicular rotator'' (i.e., its
turn-over angle becomes almost 90 degrees) on a ``turn-over timescale''
calculated to be ~ (a few)x10^6 - (a few)x10^7 yr for the examined white dwarf
models and ~ 10^1 - 10^3 yr for the examined neutron star models. Furthermore,
the initial differential rotation of the model turns to uniform rotation due to
angular momentum mixing caused by hydrodynamic Alfven waves propagating along
the poloidal magnetic field lines. Our numerical results show that, during the
turn-over phase, the spin-down time rate is large, while the spin-down power
remains small; so, the turn-over phase is a characteristic case for which an
eventually observed large spin-down time rate should not be interpreted as
implying a large spin-down power.
