Hi Tim, I've updated the title of this post ('title' meant the subject of your post, not your title - a common mistake).
Fitting a windscreen and motor is not the simplest job in the world, I'm afraid. It depends on how prepped the car was before - does it have holes in the scuttle for the main support brackets and wiper gearboxes or not? Do you have any of the wiring in place for the motor and switch?
I did mine (on a Zero which had the holes pre-drilled) during the build process, which is much easier. I recorded this in several blog posts, starting with this one, if that helps at all?
https://zerolifebuild.blogspot.com/2017/07/framed.html
If you live anywhere near Tamworth, I can recommend a member of the club who runs a garage business and you can pay him to do it for you?