Help is on the way!
To download a small tool called OnSite that will allow the support agent to share control of your computer temporarily:

Windows users click here

Mac OSX users click here
What am I downloading and how does it work?
OnSite is a remote support tool that works by temporarily installing itself on your computer in an area of your hard drive where it will be removed next time the hard drive is cleaned up.

When you start it, you and the support agent will be connected over the Internet, and they will be able to share control of your keyboard and mouse as long as you allow them to (you can abort the session at any time, and your mouse and keyboard input have a higher priority than the agent's).
Is it safe to run on my computer?
It is completely safe -- only the support agent who is assisting you will be able to gain control of your computer, and only as long as OnSite is running and you grant them access.