First, measure said window where you want to put them. Window frames are funny sometimes as they angle down a bit on the bottom to let water run off and some have inserts for removable screens etc. you can see all the different ridges in my windows in this picture.
![Image](https://i.imgur.com/CDVG86Gl.jpg)
But there was enough room on the outer edge to fit a 1x2, so that’s what I used. And enough room to overlap that with 1 x 1/4 wood.
![Image](https://i.imgur.com/sl5dpMal.jpg)
So, measure, cut and fit. In my case, was not an exact tight fit, but workable with some foam weatherstripping for last year. Once I had the frame cut, I fastened the corners with small L brackets as shown in picture. I put a piece of wood across the middle to aid in keeping the vinyl tight.
![Image](https://i.imgur.com/kbwlEq9l.jpg)
Then was time to attach the vinyl. This is thick vinyl that I purchased at Walmart in sewing dept. As you can see it’s crystal clear.
![Image](https://i.imgur.com/niBs7xcl.jpg)
![Image](https://i.imgur.com/tIwW5O8l.jpg)
I cut a piece to fit the outside area of the wood frame and used a staple gun to fasten it down at intervals, stretching it as I went. Last year I put them in place with the stapled side toward the window. Put Weatherseal around the edges, fastened a couple of clips to the window frame on each side and called it good. Was an experiment that worked very well. They just added a bit more cold weather proofing to the windows.
This year I decided to take it a step further by adding a 1x1/4 inch trim around the stapled side to make the windows fit tight without the weatherstripping. So I put the windows in place and held the 1x1/4 piece of wood against the window frame, marked where it needed cutting, put it in place and nailed a few brad nails to hold it in place, then continued all the way around, cutting and fitting the pieces with nails. Then took it off to the garage where I finished nailing it down. Basically it put the vinyl in a sandwich between the two pieces of wood. Once I put them back up, they were glove tight. Put the two clips back in the frames and done.
![Image](https://i.imgur.com/Oazz0dyl.jpg)
![Image](https://i.imgur.com/1SWx7lrl.jpg)
And you can’t really tell they are there from inside looking out.
![Image](https://i.imgur.com/ZhFRxxjl.jpg)
They aren’t professional, but they work!