Spinorial: The link on the ItsTooHard page takes you to the collection of sudoku puzzles, where you put puzzle ID 1 (as per the title of the ITH puzzle). I myself decided it must be 13 for the first one, because letter and number matched, and similarly for the other questions. In hindsight, the letters and numbers must have some significance in sudoku solving, as they seem too deliberately chosen - probably easier-to-solve cells?
They were chosen randomly. For question 1, I picked four known cells, so if you can answer that correctly you'll know you got the right puzzle. The other questions are a mix of known and unsolved cells..
JouinUP: Well, in the Too Hard Puzzle page has this link
http://www.puzzle-sudoku.com/specfic.php, then you know you need a ID and a size.
ID: the title of the Too Hard Puzzle is Ninja Giveaway '1', 1 is the ID
Size: a 3x3 sudoku it would not be enough because the positions range from A to N (1-14?) , so 4x4 is the right.
That's it, solve the sudoku and get the cells.
There may be more hints or this be the wrong way, but that's how I got it.
Yes, this is exactly how I set it up..