Please tell me how to repair lead pipe

Really,, that's all the info your going to give us?? Is the lead pipe for drainage, or water. Please let us know what the lead pipe is used for, and where the leak is, how big the leak is, etc, etc, etc, we are hear to help. But we really need some more help from you. Personally, I suggest replacing any portion of led piping. Led is pretty much a thing of the past, unless used for a shower pan, safety pan, or roof vent flashing.(even then, pretty much obsolete). Don't worry about fixing it, whatever it is,, just replace it with modern materials.