Tools needed (all attached)
1. Winimage - open extended_rom.nb with this to view contents. (winimage is a trial but lasts 30 days of use i.e. only the days you use it)
2. Dark simpsons - Htc Rom Tool - use nb to make nbh for flashing
3. Dutty's tool - to extract os.nb (windows.nb) and extended_rom.nb from rom nbh file
(note os.nb can be left out if your simply modifying existing extended rom)
1. Open extended_rom.nb with winimage - remove any cabs programs you dont want in your ext rom.
2. Extract config.txt to desktop - this gives instructions on which cabs etc to install.
3. Edit config.txt - add name of cabs in same format as shown
e.g. one i did for the touch but never used
Second line is to install a cab
Lock enabled. lock disabled, rst reset always needs to be included.
4. Add cabs via winimage - inject or drag and drop
5. Delete old config.txt and inject or drag and drop new one.
6. Right click on cabs and config.txt in winimage and set 'read only' (other wise cabs will deleted from ext rom after install)
To resize extended rom - use Image - Change format
7. Save and exit winimage.
8. Extract windows.nb from your rom using dutty's tool (enclosed) - rename os.nb. (note os.nb can be left out if your simply modifying existing extended rom)
9. Open Dark simpsons htc rom rool -rom builder - choose artemis, select System - os.nb (nb see note in step 8), ExtRom - choose your extended_rom.nb
10. Save and rom tool will make Your rom.nbh
11. Then you can flash as normal with rom update utility.
Thanks to faria for images and info that i based this tutorial on.
I've included an empty (apart from config.txt) 2mb extended rom.nb that you can use and add files too.