I agree it will not be easy and the chance of fucking it up, especially with Levy/Hitchens/Jose in charge is pretty big.
I don't have a specific person in mind to replace Kane. I think Ings is the easiest/safest name to throw out but really he is older than I would like and would be a short term solution, Maybe Ings with a guy like Daka brought in as well to hopefully take over but that is risky.
I have to think looking around Europe that many other teams seem able to function without Kane as their striker so I can't imagine that we won't be able to as well. It is unlikely we are getting one player, striker or at another position, that comes in and replaces the level Kane is at one for one so the best thing to do would be to replace Kane by increasing the talent level on the squad overall and create a team, through the players, manager, tactics, set-up, that is not so reliant on having a World Class talent up front.
But the main point remains, we have had success pre-Kane and teams around us are able to have success without having Kane or a Kane level player so there is no reason to think that we cannot do the same.