In this last chapter of the book, we present an overview of the numerical solution of the SLE, based upon a standard “test run” performed by means of the open source program SELEN \(^4\) of Spada and Melini (2019b). The readers are guided through the main logical steps of the numerical procedure, by highlighting the most critical aspects in order to avoid a “black box approach” to the solution of the SLE. The issues of the spatial and temporal discretisation of the SLE are addressed first, and tailored to the specific case study considered. The meanings of the three fundamental input parameters, i.e., (i) the rheological profile, (ii) the spatio-temporal evolution of the surface ice load, and (iii) the present relief are emphasised, also providing insight into practical aspects of the two-levels iterative approach adopted to solve the SLE. In order to illustrate the practical application of a SLE solution, a number of geophysical variables related to GIA are presented and discussed, ranging from past sea-level variations to present-day geodetic variations at GNSS stations, from the so-called GIA fingerprints to the past evolution of the Earth’s topography, from the variations of the Stokes coefficients of the gravity field to sea-level variations at TGs caused by GIA, and the drift of the Earth’s rotation pole. In each of the sections, we present the SELEN \(^4\) output data in various forms, also providing some notes about their practical evaluation. The goal is to help the readers to better capture the significance of the quantities made available to the users after the execution of the program.