I'm all for people learning stuff through videos/reading, I mean I learnt most of the stuff I know about cars (suspension, brakes, body repair, ect.) through youtube videos and reading pages and pages of other peoples attempts at doing such things. I'm not saying when I start doing all these things to my car I know it will go 100% smoothly because I watched stuff on youtube.
It's like I'm planning to refurb my wheels myself this weekend, I've watched about 5-10 different videos on it, read pages and pages of advice on it and asked people on here for advice. If there was a guy who was confirmed as doing it for a living that told me I couldn't do it I'd leave them until I can get them done properly.
But watching 1 badly filmed video on how to remove a windscreen isn't really much research as to the actual fitting, it may look simple enough to remove as well but those guys are professionals with all the correct tools and equipment to hand, what if you get halfway through then realise you need something else? Will you be able to go and get what you need or will you be stuck cause your car doesn't have a windscreen?
Phone up more then 1 company, best best is to google people in your area as smaller businesses are often cheaper (I find) then the larger companies e.g. autoglass.
Also listen to people who do it for a living.