  High-precision searches for an electric dipole moment of the neutron (nEDM)
require stable and uniform magnetic field environments. We present the recent
achievements of degaussing and equilibrating the magnetically shielded room
(MSR) for the n2EDM experiment at the Paul Scherrer Institute. We present the
final degaussing configuration that will be used for n2EDM after numerous
studies. The optimized procedure results in a residual magnetic field that has
been reduced by a factor of two. The ultra-low field is achieved with the full
magnetic-field-coil system, and a large vacuum vessel installed, both in the
MSR. In the inner volume of ~1.4 m^3, the field is now more uniform and below
300 pT. In addition, the procedure is faster and dissipates less heat into the
magnetic environment, which in turn, reduces its thermal relaxation time from
12 h down to ~1.5 h.
