Disclaimer: Use at own risk!
This is what I did to replace my likely-to-fail-if-I-used-it-much 12GB Hitachi hard drive with an IBM 40GB, 5400RPM hard drive.
Links
Sony Direct Accessories & Parts Center: C1VN Service Manual is Part Number 987212611
Tom's Hardware Guide covers installing a new HD into the C1V* PictureBooks.
HD upgrade (Japanese) with lots of pictures.
Instructions
Put PictureBook upside down. Remove memory cover and memory cover screw and the five case screws.
Put PictureBook rightside up and open PictureBook. Cover screen with something to prevent accidental damage. I used part of a manila folder cut to size.
Carefully pry the inner hinge caps off. There are three small ledges/clips around the edges of the hinge caps. It may help to
pry from multiple sides of the hinge cap so it does not slip back on.
Above the outside edges of the speaker areas are two tabs which hold the keyboard in place. The are over the extreme lower ends of the
keyboard. Push them straight forward, toward the speaker one at a time and that edge of the keyboard will pop up.
Do not lift the keyboard up; it has two ribbon cables attached for the keyboard and the TrackPoint. Rotate the keyboard bottom slowly
upward. You will need to
gently ease open the two connectors on the PictureBook motherboard. Once this is done you can gently pull one cable, then the other, straight up
until it clears its motherboard connector. Now lift the keyboard and put it out of the way.
Lift and remove the metal PCMCIA shielding.
Gently disconnect the ribbon cable at the top/center of the PictureBook from its motherboard connector using the method described above.
Gently disconnect the ribbon cable at the bottom/center of the PictureBook from its motherboard connector using the method described above. It is
attached to the TrackPoint buttons on the "Palm Rest Sub Assembly," referred to here as "top piece."
Remove the three screws in the top piece. Remove the left hinge screw. Lift off the top piece.
For the IBM 5400RPM drive I installed, I had to cut out part of the top piece so that the breathing hole on the drive was unobstructed, and
had as much room as feasible to get air. Later on, when reassembling, I had to fold the top/center ribbon cable up and tape it to the top piece
so it was not blocking the breathing hole. Scary!
Gently disconnect the ribbon cable across the hard drive from the motherboard connector on the far right side.
Unscrew/remove the 4 dark screws holding the drive holder to the PictureBook. You may have to ease out of the way the black cable covering the
top/left screw to remove it.
Gently pry the connector from the hard drive. It is at the bottom of the PictureBook on the bottom end of the hard drive.
Carefully lift the hard drive and mounting brackets from the PictureBook. Remove the mounting brackets from the drive.
Reverse the steps above for installation of the new drive and reassembly.
I originally did this replacement without cutting a hole for the airflow. The PictureBook got very hot, and kept locking up/crashing.
YMMV.