If the display is badly cracked, consider cover it with a layer of clear packing tape. This may allow a suction cup to adhere. iFixit even advises using superglue if you are totally replacing the display.

Apply a suction cup to the right edge of the screen about 5 cm from the bottom edge.

Pull up on the suction cup with firm, constant pressure to create a gap large enough to insert an opening pick no more that 5mm into the iPad.

If you find it helpful, mark the 5mm line on the opening pick with a sharpie before inserting.

Try to remember you only need to create a gap large enough for the opening pick to get in.