Are you sure that you want Remote Desktop ? For such distance helping you can use Remote Assistance.

Anyway, here's a page that sums up well both: Remote Desktop and Remote Assistance

An alternative for Remote Assistance is UltraVnc (or another VNC flavor).


Good Luck,

Cetin


Trying to unweave, unwind, unravel
And piece together the past and the future,


T. S. Eliot