i can safely say i have done hundreds of windows. always use a very sharp razor and keep the surface lubercated with something. water, windex, something!! expect to beak a number of panes. when reseating the glass, always use a light bead or caulk to reseat it. i`ve also seen so many piss poor jods where someone has substituted caulk for glazing compound. when installing push points to hold the glass in, don`t press them in tight to the panes. this many break them immediatly or even later as the glass expands. since i suffer from lead poisoning myself, i feel i can safely say to follow the previous posting. l.p. does not go away fast and can kill you`re mind and body in more ways than i care to discuss. a little research and caution makes it safe to work around lead paint. good luck and hope you`re windows turn out nice.