OK, well it's been awhile. I am not sure if Arch is a true 'livecd' in the sense that you can boot your system and mount your current hard drives. AFAIC remember it is just an install CD. So: you may well have to get a knoppix or somesuch other livecd to do this.
and after one does boot into the os how would i edit grub to boot, my boot config because i'm only experimenting is to swap drives so i think the name is hdc or hdd. thanx -tom
You need to mount the partition where your /boot lives. Depending on how you installed it may be a separate /boot partition, or it may be part of the root ie: '/' partition. Some livecd's will mount for you automatically (knoppix I think) and some you will have to do it manually.
After you manage to get it mounted, you can use any text editor to fix grub.conf, nano is easiest, vim is a bit harder if you don't know how to use it. As for the actual edits, I hope you know what you're doing as you still haven't really said what your problem is.
The more information you give, and the better you explain your problem, the easier it is for us to help you...