The best method is to download WHDLoad, and then a specific hard disk installer for each game from here:
whdload.de. There are over 1,000 game installers there, and most also fix bugs in games as well as allowing them to run from the HD.
If you copy a disk to your hard disk, and the program says "Please insert volume BLAH: in any drive", you have to add the following line to your S:user-startup file:
assign BLAH: hard-disk:path/to/blah
Although, I use "AssignZ" to manage my assigns. When such a requester appears, AssignZ gives you the ability to select where on the hard disk to assign and save it there and then without editing any files. AssignZ is on
Aminet.