[en] The main modifications which have to be done to the Lower Hybrid system are related in the change of the plasma shape in front of the grill mouth. In effect, the theoretical coupling efficiency of the LHCD grill depends only upon the density at the grill mouth and upon the launched wave index. In order to minimize the number of modifications to the launcher it is proposed to modify the length of the vacuum waveguides connecting the multijunctions to the vacuum windows. To obtain the new poloidal contour, it is proposed to recover the L1 multijunctions and to remachine their mouth. (U.K.)