Single Status Update
Yeah sure thing man. I'd recommend using one of these (I use them all the time and know them really well):
If he gets this and sets the wireless mode to WDS repeater then it should repeat the signal. He might need to add the MAC address of his main wireless device so that it knows that this is where the internet is. Tell him to update the firmware from http://www.ubnt.com as well. Will be in the airMax group of products.
I'm sure he's smart enough to do things like turn off the DHCP on this and to make sure that it has a static address that isn't going to conflict with the others. By default they come as 192.168.1.1
If he has any questions then let me know and I'll see what I can dig up!
Glad you came to me though. Wireless really is my business :-)