it is possible to edit "/system" files without root my device?

[Juan Medina]

Hi, 

I want to connect my device with adb over wifi, but I cannot connect through USB, 

so I read, If  "/default.prop" or maybe "/system/build.prop" are edited to set "service.adb.tcp.port=5555"... you are able to connect through adb.

Do you know if there is a way to edit those files without root permission? or how to connect to adb over wifi, without USB cables?

Also, which VNC tool do you recommend to mirror my android device into my pc? 

Thanks in advance.

Regards