This Tutorial complements the paper Persiano et al. (2022) as supplementary material. It is a step-by-step guide that will help the user to set up a geostatistically-based regional model (i.e., total negative deviation top-kriging, TNDTK, see e.g. Pugliese et al., 2014, 2016) for interpolating flow-duration curves (FDCs) in gauged and ungauged sites.