Alright, here's how I would update to 4.8 (assuming you have 4.5 installed with safe system enabled):
NOTE: This method will delete all of your data and you will need to reinstall all of your apps. It will not touch anything on the sd cards.
1. Download the steel droid 4.8 zip file and put it on your phone's sd card
2. Reboot phone, select recovery
3. At safestrap recovery main menu, select Backup/Restore and perform a backup
4. After backup completes, return to the main menu
5. Select mounts/storage
6. scroll to format /system and select it
7. Repeat with /data and /cache
8. Return to main menu
9. Select install zip from sdcard
10. Navigate to the file and begin install
11. Once install is complete, return to main menu
12. Select Wipe Cache Partition
13. Once that completes, from main menu, select Advanced
14. From Advanced menu, select Wipe Dalvik Cache
15. Once that is complete, go back to main menu and select reboot phone.
You should be booting into steel droid 4.8 at this point. If you choose to install any of the addons, put them on your sd card, and repeat steps 9-15. I hope I'm not forgetting anything.