Perhaps it's to easy
Just take a new CF-card.
Load MyBIOS.
You are at the bootscreen.
press/hold START+SELECT+OPTION.
You enter the myide-menu.
Do a init, save&exit. (You do not need partitions, only images, they are now set to be usable)
You are back at the bootscreen.
press/hold START.
voila, you are in the MyBIOS image-mode.
All slots are now empty, start copying now from a drive/sio2pc, or use the myide-manager (for PC) to copy ATR there.
Check the image-section in the manual.
Plus the addition keys, supported to swap disks and to write enable images.
Later
Sijmen.