Moving iPhoto image files to another disk

My Mac Pro start-up disk is full and I need to move the image files from my existing iPhoto Library to another disk. I have started loading new photos this way already but how could I move the old images and still have iPhoto reference them correctly?

Many thanks.

Why not just:

a. copy the existing iPhoto Library to the new disk (the entire iPhoto Library package)
b. start up iPhoto holding the option key down
c. direct it to the "new" iPhoto Library on the new disk

Once you've verified that everything's working as it should, you can delete the old library. As always, I'd suggest making a backup before doing anything risky.

many thanks for suggestion - that would certainly work. However I am now also using other photo S/W like Lightroom so like my image files accessible by multiple applications. Is there anyway of extracting the image files from my current iPhoto Library so they can be accessed as raw files again?