I have no idea, unless we're talking (part) fan ownership or just by getting lucky with an owner that actually cares about the fans.
Fan ownership was discussed on football weekly (I think) at one point, with their German panelist Raphael Honigstein essentially saying that for the big clubs in England it's unobtainable because of how far the money part of English football has spiraled. Looking at Spurs as an example it would probably mean raising a billion or more to buy the club outright. Even if you got a hundred thousand fans to join in to buy the club it would mean raising ten thousand pounds from each of them on average. Even half that for a part ownership thingy seems completely unrealistic, even a tenth of it seems downright impossible just from a financial point of view - never mind logistically. Unless we get relegated by a few divisions without losing a lot of our fanbase and without accruing massive debt it's just not going to happen.
I really think having an owner that, at least for now, has his interests aligned with most of what most of the fans want is about as good as it's going to get. Just ask United, Liverpool or even Arsenal fans - ignoring the truly shocking stories of clubs that are sometimes described as just extreme cases when poor owners are being discussed.
Rarely does the complete inability of fans to influence the club get more apparent when a change of ownership is on the cards. The previous United owners had seen the club get astonishingly successful on the pitch and off the pitch. They were reportedly United fans themselves, with a long term ownership interest in the club. Didn't matter one iota when the Glazers made them a better offer than any other potential owner. Look at the string of owners at Portsmouth and Leeds. The fans have absolutely no say on something like this. No amount of protesting or booing will help. Even the sometimes threatened, never actually realized walk-out/stop going to games would not change an owner's decision of who to sell to (although I suppose it could, possibly, arguably, stop someone from buying a club - although that also looks unlikely).