So here is an idea, why don't they ask the SFMOMA experts if there is any way to remove the entire wall and donate it to their collection? I have seen Banksy pieces where they cutout the entire external wall an office building and displayed it in an art gallery for sale (granted not this large). Seems like a win win, the school district gets the mural down and a new wall to paint however they like. SF MOMA gets a critical piece in their collection and I'm sure all the controversy will spike its total worth. Granted cost would probably be substantially more, but perhaps the SF MOMA can help with that since they have a large endowment and would be receiving the piece.