Boot Freeze - How do I access F18 on the HD?

Hi, this may seem a trivial question to some - apologies for this.

I have F18 installed. Because I work with images it is important to have optimal screen resolution, which F18 doesn't allow in my case.

Following some advice on this I added two files to the xconf.d directory to achieve the 1600x1200 resolution the monitor is capable of. However, the result of this is that the OS now doesn't boot.

It would be simple enough to remove those files to solve the boot problem. But try as I might I cannot access the F18 installation on the hard drive. I have tried to use a rescue disk with no success (it works but I seem unable to mount the relevant partition). Other procedures seem quite cryptic, or at least I don't understand them.

What can I do?

thanks


MZ