The modification of existing and assembled electrical printed circuit boards is accomplished by placing additional conductors between the lead wires (4) of the electrical components (2). These conductors are in the form of a printed conductor foil (3) which is placed on the support plate (1) of the printed circuit module. The ends of the conductors on the conductor foil (3) terminate in soldering eyelets which are soldered to the protruding lead wires (4). By this means all additional electrical connections can be made at one time and without the danger of routing errors.