The Electromagnetic Calorimeter (ECAL) barrel of CMS experiment at CERN is made of 36 Supermodules (SM), each consisting of 1700 lead tungstate scintillating crystals. Each SM weights 2.7 tons and is a highly sensitive and fragile object. The SMs, 18 per each side of CMS barrel, were successfully inserted inside the Hadronic Calorimeter (HCAL) barrel of CMS in 2007 with a dedicated insertion tool called ”Enfourneur” (E1). The movements of the E1 are controlled by a fine adjustment system for the SM insertion and extraction. During the Long Shutdown 3 foreseen in 2026, the E1 will be used to extract the SMs for their electronics upgrade in view of the HL-LHC future runs and to insert the SMs again in CMS. Based on the past operations, modifications on the current E1 have been implemented to improve and facilitate the functionalities, in compliance with the up-to-date international standards concerning machinery safety and CERN internal applicable rules. This work was carried out through several stages and iterations covering a complete design study, FEA simulation within the scope of Eurocode 3, installation of the modifications, and validation tests. The modified E1 fulfills all the intended technical and safety requirements. In this paper, a review of the E1 functionalities, the applied modifications, and the performed validation tests will be presented.