Here is the command to get familiar with. chdman -createhd \\.\PHYSICALDRIVE"n" image.chd "n" is the drive number as seen by windows drive manager.
If you are using Windows 7, then you have to run chdman as administrator.
Try it out. Do a dry run with a spare hard drive attached via ide or USB external.
But; some things you can do first. 1. Order that camera card drive and a small but speedy card. - this will be your gift to the guy for being so kind as to give you access to the machine. With any luck, the drive will boost the speed of game boot.
Make a video of the game since none are available. Probably be good to do a boot up video as well. Note any boot errors. By now, the MB battery is probably dead.
Before you remove anything, make sure you know whats working and what is not. For example, do all the contact points work on game? Do all the speakers work? Do all the lights work? Does the game boot without errors?
You'll probably be pulling the PC case out of the machine to take home. Be sure to take photos and label any cables you disconnect so it all makes sense when you put it back together.
If the game has a manual and or schematics, grab them too for backing up. Flyer too.