You can't valve is in hurry to develop Dota 2 and they wont be adding less important things like this anytime soon.
And since game is only in beta there aren't any good mods or 3rd party scripts to change that.
As Drake mentioned there is a petition on dota forums to add that option an it has a nice number of supporters,so it is possible they add the option before final release of the game.
There is only 1 popular mod out there(for now) that changes dota 2 a bit,but it still doesn't have the option to change minimap location,and the stability is terrible it crashes the game and with every beta update half the things stop working.
In case you have problems with clicking on minimap by accident you can change dota_minimap_misclick_time which is basically the time that you have to hover your mouse over the minimap before you can click it. I think the default value is 0.4.
Just write in console: dota_minimap_misclick_time "TIMEINSECONDS"