Fling a few missiles around ineffectively
Keep provoking US forces in the region and messing with shipping in the gulf until US decides to put troops in
Go down in flames and take US with it

I think the US will eventually 'have to' put troops on the ground, whether the regime falls and they go in to secure nuke materials or as an actual invasion. But the terrain in Iran like the worst of Afghanistan and they'd be fighting against a population double the size and far more advanced/educated than Afghanis, over an area about 40% as big as the USA
Also good luck getting help from a bunch of NATO allies etc like in Iraq, Canada and the EU dislike and distrust the US now, Japan condemned the Israeli bombing of Iran and has been rejecting US demands on trade and defense issues for a few months now

I don't think Iran can win or break even here, but they can drag the US into another 20-30 year quagmire