  We describe a method of implementing the axisymmetric evolution of
general-relativistic hydrodynamics and magnetohydrodynamics through
modification of a multipatch grid scheme. In order to ease the computational
requirements required to evolve the post-merger phase of systems involving
binary compact massive objects in numerical relativity, it is often beneficial
to take advantage of these system's tendency to rapidly settle into states that
are nearly axisymmetric, allowing for 2D evolution of secular timescales. We
implement this scheme in the spectral Einstein code and show the results of
application of this method to four test systems including viscosity, magnetic
fields, and neutrino radiation transport. Our results show that this method can
be used to quickly allow already existing 3D infrastructure that makes use of
local coordinate system transformations to be made to run in axisymmetric 2D
with the flexible grid creation capabilities of multipatch methods. Our code
tests include a simple model of a binary neutron star postmerger remnant, for
which we confirm the formation of a massive torus which is a promising source
of post-merger ejecta.
