Icaros Desktop 2.0.3 can be updated to version 2.1 through LUPD (LiveUpdater), however, you should delete everything related to OWB before updating. This is important: otherwise, Icaros will surely work after updating, but OWB will behave in umpredictable ways. So, this is the correct procedure.
First of all, close all running programs. Best of all, open Prefs/Icaros Settings and disable Amibridge if running at startup, disable FTP file sharing, disable any program running ad startup, and restart AROS. Then, follow these steps:
1. Run Tools/LUPD/LiveUpdater or OWB and download IcarosUpdate_203_201.zip update file. If you've used OWB, close it.
2. Open your system drive with either Magellan or Wanderer
3. Move to your Utilities drawer
4. Select OWB drawer and delete it
5. Move back to the root of your system drive
6. select Show -> All files. Even better: choose the name view in Magellan
7. move to the Prefs/Env-Archive/Zune subfolder
8. locate the OWB.x.prefs (x is a number which may change), delete it
9. if you closed LUPD, run Tools/LUPD/LiveUpdater
10. select updating by file, locate the IcarosUpdate_203_210.zip file
11. follow instructions on the screen, wait for the update procedure to end, then reboot when prompted