It took awhile but the router and firewall are finally installed in the customer site with the help of G.
Okay, basically, without G's help, I would have been unable to do it. The customer had two connections to us, a wireless connection (at 10Mbps) and a T-1 (at 1.5Mbps). The connection should handle all the traffic but if it goes down, the T-1 should take over. Such a configuration can't be done using static routes (which is what I'm familiar with) but requires something like OSPF, which is beyond my ability.
Sure, it took longer than expected, but then again, the current configuration was rather “interesting” (and not in a good way). Also, the configuration in the old customer router didn't survive a power cycle (whoever configured the old router forgot to save the configuration into non-volatile memory—one momentary lapse of power and it's hand-configuration time again) but since we were already connected using the new router it wasn't much of an issue.
G also left behind some light reading in the form of several feet of documentation on Cisco routers (stuff like Everything you Wanted To Know About Cisco Routers But Were Too Ignorant to Ask and Teach Yourself Cisco Routers In a Thousand and One Days) which was kind of him.