The replacing of the view window just took a little time, I first removed the broken one by unscrewing it and then used a spatula to separate the window from the boat, I used that as a template. I bought the plexiglass via ebay, 3/16" x 24' x 24", 1 sheet is enough to make both view ports, if you want to make both, cost about $40 including shipping. I use a standard Jig Saw to cut it out, standard blade, fine blade seemed to melt it too much. You have to be careful when drillling, use an old drill bit, a sharp one can chip the edges when drilling. I put a radus on the edge with my router, taking a little material off at a time. Then reinstalled using silcone sealant.
For scratches on plastic there is a product you can use called NOVUS, polishes plastic, takes the scratches out, about $15 on ebay.