Determine those levels at which the stock has found support or resistance in the past.
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Depends on the bar interval. There's no reason to go back months if you're trading a 5m bar. Plus highs and lows that are evident on intraday charts may not even appear on daily charts.
If it's pivot levels you're interested in, there are two threads under Trading. Just do a Search using "pivot". However, the pivots do not necessarily provide S/R.