What Do you need to know?
You should also know that doing this will usually wipe all the info off your phone(except the microdrive and SD card)
So it is important that you learn to backup any info that you want to keep.
I suggest using pimbackup and I usually back up MyDocuments by syncing with your computer or even copying it to your SD card.
I do this as a routine everytime I fiddle with my ROM so I can return to the previous state.
I also use Sprite Backup as well.
Remove Sim/Sd card
Next , make sure you remove your SD card and simcard before proceeding to apply Olipros unlocker
Well you have to unlock your ppc to accept a new ROM.
I haven't done this for a while , but fortunately the process has been made easy by Olipro in this thread
and in german in this thread
Check Bootloader Screen
Throughout this forum you will be referred to your SPL.
This is the Secondary Program Language and on your unadulterated ppc it will be 1.1
Olipro's original unlocker upgraded this to 1.1x but the unlocker above will change it to SPL 1.2
You can see if this has already been done by putting your phone into the Bootloader screen.
This is done by holding the camera button completely in and then pressing the reset button.
You will now see a red/green/blue and white striped screen telling you the device id and SPL version.
If you see SPL 1.2 , you are good to go to load any SPL 1.2 Rom.
Activsync/Windows mobile device centre.
You need this program to apply updates to your ROM
There used to be a problem with earlier versions of these programs not recognising WM6 ROMS.
This problem is easily solved by updating these programs
No there is no FM radio on the Athena, this refers to the operating System radio that operates the phone/wifi/gps etc
This is important to know as AP4 needs at least radio 1.50 (and maybe WM6.1roms)
Upgrading the radio proceeds the same way as a rom upgrade
version1.58 is here http://forum.xda-developers.com/showthread.php?t=409271
version1.57 is here http://forum.xda-developers.com/showthread.php?t=372904
Where to find a ROM
Fortunately Sergiopi has collected and sorted them here
Walk me through the Process
2.remove sim and SD card,apply hard reset and wait till full initialization complete before connecting to pc.
3.establish Activsync connection
4.ensure no background program running, antivirus, firewall and etc. before executing flash command.
5 start the unlocker and follow the instructions.
6.reboot phone and make sure you still have activesync
7.**Update the ROM to an SPL appropriate rom according to what appears on your bootloader screen**
following the above protocol
Now you should have a new ROM to play with!
And play with it you should !
But I want to try an SPL3.5 ROM!
OK if you got this far You should be able to do this.
**First step is to install AP4**
At the moment there is only 1 foolproof way to do this and this is to use the Athena Updater
But first read the upgrade Guide Please Here http://www.htc-hackers.com/uploads/AP4_How_To_1.8.pdf
It is very detailed and I recommend following it exactly !!
This is the link to the athena Updater
Now I want to go back to SPL 1.2
Ok. this is possible
see here http://forum.xda-developers.com/showthread.php?t=405604
Need to know more or Stuffed the Flash?
Don't worry , nearly everyone here has made a mistake but been able to recover.
Read the wiki and/ or search the forum
If you have any suggestions to change What I have written ,post a reply.