GH_Structure delete data at certain path

I want to access a path of a data tree, delete all data found there (a list of Type GH_Number) and append a new list (of Type GH_Number). How do I do that? I searched through the SDK and did not find a suitable method.
I was thinking about using the RemovePath method, but then I dont know if all the data associated with the path (meaning the data on higher levels) would get deleted too.

Thanks for your answers / hints!