glazing bead for my windows is sold at Home Depot. Used a stiff scraper to pop out the front edge then pliers to grab the strip and gently work it out. it is held in places by the window sealant, but you can still get it out. cut the new one to size with shears and pop it in using the scraper again. with a lot of practice I have been able to replace a strip in less than 5 minutes.
the lad, April 2010