Change Board Rusting Cover Xsara 2.0 HDI 90CV

Good, I am going to change to the Xsara the Balance cover joint and I am seeing that once the screws and admission tubes have been removed, in the left side, where an electrical connection goes, a part of the lid is put in a hard plastic housing, and I do not know if it is necessary to remove it too and if it is easy to remove. All the best.