Politeness says that you don't remove or damage facts others have entered.
Your request has some different possible interpretations - what do you want to do, exactly?
- Remove information you have entered about your family, leaving information others have entered?
- Remove information about living people in your family that others have entered?
- Disentangle a merged tree from others' data, and delete only the parts you have entered?
The last one is very difficult. The others are possible.