Ok I've done this so I'll explain. Please remember - this is not for the FAINT OF HEART!
Step 1 - BACKUP YOUR PST
Step 2 - Confirm you got a good backup (IE: Just copy your .PST file so if you break it, your not screwed)
Step 3 - Download Notepad++ (looks like you already did this)
Step 4 - Enable the HexEditor Plugin.
To enable the HexEditor for Notepad++ do the following:
A: Open Notepad++
B: Click Plugins, Plugin Manager, Show Plugin Manager
C: Click Settings Button on bottom of Plugin Manager Window
D: Check Box " Show unstable plugins " and Click OK
E: Scroll down and Check Box " HEX-Editor " and Click Install Button
At this point the Hex-Editor will install and tell you to close your Notepad++ to save the changes.
Step 4 - Re-Open Notepad++ and open a COPY of the Pst file you want to corrupt
Step 5 - Click the Hex button to view the file in HEX mode
Hex - 7.jpg[/attachment]
Step 7 - Press Spacebar 7 times. This will clear positions 7 through 13 on line 1. You will notice the space will delete the data and on the left 20's will be displayed on Address 6 - C as shown below
Now, save the file and continue with the instructions from ShockerSH to repair the PST file you JUST corrupted. :)