My brother gave me his shattered iPad 3 screen for free...lucky me.
I have repaired various iDevices for fun and I would have to say...this one is the most straight forward. It took less time to repair than an iPhone. The process took me a little longer since most of the original class was shattered into tiny shards of glass. It took me about 45min to an hour. I had to meticulously scrape off the double sided tape and bits of glass, bend the aluminum back corners and remove the display bevel and tape. I prefer using a heat gun on a low setting to separate/ remove the tape holding the screen in place. It was more effective than a hair dryer or the iopener.
If your glass is super shattered...and not just cracked, I applied packing tape across the whole display before starting. This allowed me to work the display as one piece as much as possible. Make sure you wear latex or latex free gloves so you don't transfer any oils onto the back side of the new screen or the lcd. I made the mistake of scratching my forehead with my gloved hand...and left a little smudge on the underside of the screen....so try and refrain from touching your face. In addition, keep a can of air near by. Make sure you don't get little pieces of glass under your iPad while you are working. Last thing you want to make scratches into the back of your iPad.