Sorry I can`t help you with instructions for ID as I'm not familiar with the ID web editor. I just use JOSM as it is much better. But I can perform the change for you if you like. Please give me instructions where to change the name. From your description it looks to me as if the name "Route de Dampierre" needs to be replaced on all the segments, such that there does not remain any segment with that name finally. Please confirm.