Normal mode analysis (NMA) is an old and well established technique that has recently found many new applications in the field of structural biology and structural bioinformatics. Here we present a user guide for new computational scheme for nonlinear normal mode analysis that extrapolates a motion computed from instantaneous linear and angular velocities to large amplitudes. The method is available at https://team.inria.fr/nano-d/software/nolb-normal-modes/.