Upgrading SH-152A firmware in Win XP

Hi there,
I have a Samsung SH-152a CD-Rom drive and recently upgraded to Win XP.
The drive then failed to recognise burnt CD-Roms. (It would still play audio CDs.)
I found the new firmware C506 on Samsung’s website. (I seem to have been using C503)
I am having trouble installing the new firmware.
I am finding the upgrade instructions hard to follow.
Could anyone walk me through installing it in dos in winxp?

What is the problem with the flashing instruction?

Obviously you have to flash the drive from REAL DOS.