Insuflate it (snort it) after crushing it very well (preferably with a pill grinder which you can find at walgreens). Opana crushed insuflated is the best opiate high I have ever had, and I have had oxycodone OP/Insuflated, Dilaudid IV 6 mg, Morphine IV many mgs, Poppy Pod Tea (which is quite incredible), codeine, hydrocodone, fentanyl, methadone... etc.
Please make sure that your dosage correlates with your tolerance level so you do not OD. Make sure someone is with you if you are not positive about the dosage. I did 20mgs insuflated, sometimes 30, but my tolerance is very high.
I will agree with Death&Decay^ that Opana isn't as euphoric as oxycodone insuflated, but it is more of an upper opiate feeling. It has a lot of euphoria to me... the insuflated 'high duration' was longer than oxycodone IMO