9005's are for high beams.

You don't have to DO anything. Take out the old one, put in the new one. G4 Prelude high beams use a 9005 bulb.

9005 is brighter and a higher wattage than 9006. If you've already got HID in your low beams, get the number 9006 out of your head and don't worry about what it's for. Only worry about 9005's. That's all you need to know. 9005's are high beam bulbs.