FASER, the Forward Search Experiment, at the LHC aims to study neutrino interactions with the unexplored high energy range and to search for light, weakly-interacting new particles. The particle detector is placed at the LHC tunnel 480 m downstream of the ATLAS interaction point along the beam collision axis. The place is an ideal location to detect neutrinos since charged particles produced in the interaction point are deflected by LHC magnets and neutral hadrons are absorbed in 100 m of rock. FASERν is a neutrino detector, composed of an emulsion tungsten detector with a target mass of 1.1 tons, veto scintillators and interface tracker to the spectrometer. Approximately 10,000 neutrinos will be detected in LHC Run 3 and three flavor neutrino cross-sections will be measured in the energy range from a few 100 GeV to 5 TeV. Furthermore, the neutral current interactions and the channels associated with a heavy quark (charm or beauty) will be studied. Here, we present the assembling and installation of the FASERν detector for the physics run of Run 3. We also present the status of the development of the simulation and the reconstruction framework.