You are planning to change your IT hardware but above all you have to get rid of your existing equipment. The various European and French directives concerning the recycling of electrical and IT equipment require that you ensure its proper disposal at the end of its life.
As a professional generating WEEE (Waste Electronic and Electrical Equipment), you are responsible for its processing (depollution, dismantling and preparation for final disposal or recovery) and recovery (reuse, recycling or incineration).