I suggest windshieldstogo.com. They ask you your zip code, the year of your vehicle, the make of your vehicle, the model of your vehicle, the vehicle's body style, and the part you need.
Your local auto parts store can sell you the simple tools needed to help you remove the windshield trim without damaging the trim or the glass.
Some great companies offering windshield glass replacement include for example "Safelite", "Glass Doctor", "Windshields To Go" and "Windshield Experts".
Glass shelving can be bought at the online Argos Shop, Wayfair, ShelvingShop, the Home Depot online store, JohnLewis, the IKEA online store, BigW and OneDayGlass. Alternatively, other common online merchanting websites such as Amazon and eBay will also have glass shelving in stock.
Keep in mind a windshield takes a lot more abuse than a store front and there is typically only an 1/8" hole on the outside of the glass so that is the only thing exposed to the elements at all is that area, which takes 2 minutes to resurface if necessary.
You should pay around $100-$250 for windshield glass repair.
You might look at your local yellow pages under "Auto Repair- Glass" or "Windshields" to find a local company who can insert a resin into your windshield to prevent the crack from spreading and needing a full windshield replacement.
Glass Christmas trees can be purchased both online and in store. Online you can buy glass Christmas trees anytime of year. In store they tend to be a seasonal item available in most types of stores during the Christmas holiday season.
There are websites like YouTube that will show you how to replace the windshield on your own. You can find the custom made motorcraft parts glass at online shops like fordparts.com.
Windshield repair and replacement can be very simple. If your windshield is cracked or chipped, the store will use a special kind of melted glass or resin to seal up the damage. If the windshield needs to be repaired, then they will use a process to remove it without damaging your car frame and simply switch it with a new one.
In the windshield glass.
Best to call a glass co. to do it as the old glass has to be cut out and everything around the windshield cleaned before the new glass with urethane on it can be set back in place.
A Mercury Cougar windshield will run about $230 according to online auto glass shops. However, that price is location based so expect a slightly different price based on your location.