chance of beating DWI.. very low... unless the officer made a mistake in pulling him over.. then all evidence gathered is considered Inadmissible so case will be dismissed... but that rarely happens.

your best option is get a decent lawyer for the price and get a plea deal... i think this is his first time this happened...

also make sure about how that might affect immigration status...

if he is sentenced to more than 1 year.. that equals deportation.. so becareful... some of these US laws are crazy.

good luck.