Default [Q] Rooting a chinese smartphone with broken lcd screen.

Hello everyone,

My aunt gave me a chinese smartphone (n9000 i9220 pad) with the lcd screen broken.
I tried to control it from my pc with this software (Droid@Screen). It NEEDS USB debugging to be activated in order to work. Since my aunt obviously didn't have it activated, I could only see the smartphone's screen when I entered to recovery (Where i think debugging it's activated by default). So I need to activate the USB debugging option with no image from the smartphone. To archieve this, I found a solution that consists in editing manually a file on /system, but since it's not rooted, I don't have write permissions on /system.

I'm not gonna die if I can't do this, but I want to know if it's really possible.

More info:
Exact model: e1809l_v75_gq1008_ov5647_v20

*I can access the smartphone with adb, so If anyone needs more info that I could retrieve from it, just tell me.