Disaster relief help for Mexico city.

Dear Librecad friends!
I have one question:
Im dealing with an old cadastrian file of Mexico city, that I need to offer disaster relief.

i need to close some poligons that mark the limit of properties. I have in one layer the property limit, in other the street limit and in other the construction perimeter.

Is there a form to make a cut of one layer over other and then join the cut pieces in one poligon?

Thanks in advance.

Javier García Prieto.