When I started the game I joined the Stormcloaks, because it was the only quest I had. I kind of regret joining the Stormcloaks, now, though. I finished "Battle for Whiterun" and now theres a new Jarl and every guard is now a Stormcloak. If I used console commands to delete the main quests, would there be regular guards everywhere, and would Jarl Balgruuf still be Jarl?
It may be possible to pull this off with a long, complex series of console commands, but you're as likely to break your game as you are to fix it. Probably more likely.
In terms of normal gameplay, you're past the point of no return, which is the Jagged Crown quest. See this other question for details on switching sides.