I've dismantled an iPad and it's not for the feint hearted. As Michael says there are videos on Youtube but they don't really convey the full horror.
First step to remove the screen is warming it all around the edge with a hair drier. This softens the adhesive to a tacky consistency (everything is held behind the glass screen which is glued in place). Then you pry the glass away from the metal body using a guitar plectrum or a special tool of similar thickness. Clearly the glass bends a fair bit during this process and if you are hoping to reuse it, this is a risky operation.
The real difficulty is removing the screen / digitiser without damaging any of the multiple ribbon cables that are strung around the periphery of the body. These connect the switches, cameras, wifi aerial etc to the main boards and are positioned like a fiendish perimeter trap. If you poke the tool anywhere near them they demise. Despite watching the videos beforehand, I managed to liquidise several of them. The replacements are surprisingly cheap but the job easily develops legs and runs off on you.
My daughter's iPad is still working although the replacement screen I fitted is now holed in several places(!). But I won't be attempting another repair.
So yes, it is possible to do it yourself but it's like changing car tires with a couple of spades and a crowbar – been there, done that but it's far better to get someone experienced to do it properly with the right tools..