I have an old Dell XPS M1530. I just replaced the hard drive with an SSD and installed Windows 8. I was wondering if it's possible for me to replace the screen with a touch screen LCD panel and use that with Windows 8.
Replacing a monitor screen that's not the same part number (or direct replacement) for your particular screen model is almost impossible, even without added functionality.
Now in theory, provided that touchscreen information goes back through USB or PS/2 serial, it could be possible to solder the signals to the motherboard if the monitor pins would fit in the monitor connector (or could be made to fit), but even if this is true, it's an extremely difficult task even for a seasoned laptop hardware tweaker, and absolutely nothing like replacing a hard drive.