My lead water mains pipe sprung a leak how do I fix it ?/

Where are you located and what leads you to think you have a lead supply main? Can you post a picture? In most cases the pipe must be cut and spliced or completely replaced. Back to you

My lead water mains pipe sprung a leak how do i fix it ?/

This would be your water service from the pump or city water? What material
Is the pipe? Pkastic or galvanized? Where's the leak? Hole in the pipe or a leaky fitting? Let me know. Tom