The project consisted of the conversion to 25 KV of the Legendre district substation (electrical mandate, control and power.) We had to find solutions in order to make the transfers transparently for the operations. 7 secondary distribution stations, and the transfer of loads have undergone modifications, and 2 stations have been rectified at 750 VDC. Tight preparation and planning with the client made it possible to carry out these critical tasks, for some, during a single weekend, including dismantling, pouring concrete for cleanliness bases, setting up transformers and distribution cells, connection of loads, and start-up.