Here's an easy way to remove guidelines from scanned calligraphy in Photoshop. Scan (in color) your calligraphy with its guidelines. Open the scanned file in Photoshop, and then open a black and white adjustment layer. (One way to do this is to first select the calligraphy layer by clicking on it in the Layers tab, and then choose Layer/New Adjustment Layer/Black & White from the main menu.) Then fiddle with the color sliders for that adjustment layer until your guidelines disappear. That's it! The idea behind the method is that with this adjustment layer, you can control how each color gets converted to black and white, so whatever color your guidelines are, just crank up the slider(s) for that color all the way to white, and your guidelines will completely disappear into the white background.
Once you have done this, you have a black and white image of your calligraphy without the guidelines, and from there you can apply any other techniques you like to the calligraphy. (For example, you could use Apply Image to make a mask of it, as I described in the Scanned calligraphy in Photoshop without the Magic Wand thread. That would allow you to put colors back into the image.)
I have demonstrated this here with two images: the original with the blue guidelines, and the new black-and-white version without the guidelines. The only slider that I adjusted to get the version without the guidelines is the "Cyans" slider, which I put at its maximum.