I do not look to "undermine" my fellow mopar enthusiast, but ,,, leading is very difficult , even for those of us with many years of autobody trade under our belt. First, you need beeswax, and a paddle, several sticks of lead ,and depending upon your skill, what grade of lead, (some have lower melting points than others, which effects flow and workability). Also needed is rubyfluid... a flux that is necessary to make lead flow over metal, then the art comes into play.
Once you have lead melted into place , it needs to be "sweated" .. this means to remove any traped flux (rubyfluid) that is caught below the surface ,brought to the surface for removal. (and if you can do this as a novice without dropping huge amounts of your repairwork onto the floor,, you are awesome!)
Long and short is ,, skip the lead, use Duraglass instead, it is very user-friendly, and will hold out very well ... so help me wang.,.......