To me I rather pay the $50-$100 bucks to get that ish down professionally.. this way if they're responsible if the defogger lines get mesed up.. they estimate 1-2 hours but I have easily picture it taking more than that.. especially since most of us would be doing it for the first time.. I usually take the front 2 off every 2 yrs for inspection and that takes me anywhere from 1-2 hours.. scrapping the adhensive clear is a muthaf*KKa.. Remember this without having to be careful for the defogger lines...

This is just me tho...