Ok I'm gonna create/sticky this thread since I'm too lazy to hunt/post instructions for it every time it's needed lol
With TeamViewer you can remotely control any computer as if you were sitting right in front of it - even through firewalls.
Your partner just has to start a little application which does not even require an installation or administrative rights.
For live technical support, (when requested), download TeamViewer from: http://www.teamviewer.com/index.aspx
And PM me the 9 digit code + access code. Do not post it here.