Ready to install windshields, any suggestions

I would use new rubber seals unless you can take the old ones and bend them double without any cracking all the way around them.I use a little WD-40 for a lubricant and a thin sciem of silicon for extra insurance I would not use the urethane god help you if you have to take it back out.I use that for sealing wheel tubes and putting on hood scoops wen it gets hard its there to stay and use the plastic spoons as stated above and if you have to tap it down use the flat of your hand.no sharp hard tools.after its in slap it with your hand all around to help seat it in..and its good to have a helper.....or find a man running around in one of them glass vans and offer them a little money on the side to come buy and put it in..that's my 2 cents worth........Artie