Read FAQ above.
Have a damn good excuse which must be backed up with a better than average score the second time around. Apply BROADLY. If the rest of your app looks good (grades, clinicals, letters, etc) then the detrimental aspects of a failed step I can be mitigated. Take Step II early and crush it as well.
If you are an AMG it makes things easier. Follow the above easier said than done advice and you should be ok.