You don't, thats the way its wired. I have the same. If i remember correctly there is a relay that comes with the lights
that switches of the low beam when high beam is selected. You will find you don't need the lows when on high anyway.
I think it could have something to do with excessive heat build up or something, I could be wrong. Anyway, the projector low beam is a cut off beam which means the beams end abruptly. It is completely different to a standard headlight. I found it doesn't serve any purpose or make any difference if the low beam is on or not.
If thats the way they are designed, don't go altering them. You will probably stuff the lights and more than likely void the warranty.