I can install the downloaded one with no issues. However i want to remove the package in /Library/Updates/Rosetta. If I boot into recovery mode and goto /Volumes/Machintosh HD/Library there is no Updates directory there and hence I can not delete the rogue Rosetta directory.
The Updates folder in question lives in the apfs volume 'Macintosh HD - Data' and that's not mounted in the recovery environment until you decrypt and mount it using a diskutil command, after which you can 'rm -rf' the Updates/Rosetta directory. That's how I did things, but since a simple typo can corrupt your disk, I suggest using the much safer approach mentioned by
@bogdanw above, i.e. turn off SIP and then use Finder to remove the directory.
To turn off SIP, boot to recovery, open a terminal from the Utilities menu, and in it type
Then use the Apple menu (upper left) to reboot. Log in and navigate to /Library/Updates in the Finder (use Go -> Go to Folder... in the Finder menu). Now drag the Rosetta folder to the trash and empty the trash. You'll probably want to turn SIP back on now, so boot again to recovery and open a terminal. In it type
Use the Apple menu to reboot.