[eenieMINI]

OK Here is my method,

Preparation:

1. Download and Install current version of Desktop Manager.
2. Sync your phone to PC to be sure all drivers load and DM sees your phone.
3. Download OS exe of your choice. Be sure its specific to your phone model. Some OS have same number/version but are for different models.
4. 4. Check Add/Remove Programs for other OS installs and unisntall (on PC).
5. Reboot PC
6. Take SD card out of phone. SD card data has been known to become corrupt during OS install and the result is spontaneous reboots of your phone later. I make a backup of SD card on my PC, take card out of phone. When all updates/installs are complete I replace SD card in phone, format from phone and then move the data back from PC. May by overkill but it has stopped the spontaneous boots for me so I continue to do it.

Now you're ready to start:

1. Install OS exe by clicking on downloaded file.
2. Go to \Program Files(x86)\Common Files\Research in Motion\Loader Files and delete "vendor.xml" or rename to .old (IF running OS that is not from your carrier, IE leak or hybrid)
3. Backup Device: connect to DM go to Backup/Restore then do a backup.
4. Back up 3rd Party installs (optional as you can always reinstall from vendor) using BBSAK v1.7. To do this run BBSAK as admin (do not use the shortcut go directly to the bbsak.exe in folder). Click Backup/Restore then Backup Apps. Caution: watch your phone! you will see the give/take arrows transferring data, the program on PC will have a popup almost immediately saying success but do not disconnect until you see all the apps in a list window and phone is no longer transferring data, the popup is out of sequence.

OK the fun stuff....
Two ways to go, it doesn't matter which is first so you choose.
I like to keep BBSAK connected and then choose Wipe Device right after I backup. When this happens you get a warning "low level wipe" accept it.
Watch phone, you'll end up with a reboot and a white screen: you're ready!!

You can then load OS using BBSAK and directing to the OS folder (which sometimes loader finds and sometimes not). OR you can use ShrinkAOS to shrink then load your OS.

I use SAOS method because I have to manually direct to the OS folder so I know I'm loading the right one. So Run SAOS as admin, point to the program files(x86)\common files\Research in motion\shared\Loader files and pick the folder of the OS you just installed. Click on any standard app you want to remove or leave it alone your choice. then click "shrink my OS" then click Load OS. Be sure in the next box to check off those standard BB programs like notes, messenger, docs to go stuff or they won't load. And away you go.

Now, OS loads, phone reboots. I then pull battery for 30 seconds. When rebooted again, I begin restore. First use connect to BBSAK and then choose, Modify CODS then LOAD CODS (the restore method has never worked for me so I do it this way). Navigate to backup folder in the BBSAK program folder. Select all or those that you want to run on your new OS. (Be sure they are level compatible like 4.x or 5.x sometimes you need to load updated versions). load, reboot.

Last part: connect to PC one last time. open DM and then do backup/restore, click Advanced! then in the window that comes use the drop down to load the backup you made earlier, should be dated. Go through and highlight the calendar (if you have calendars synced via google/outlook you want to delete this part of the save and resync outwardly instead, if you don't then you can skip this step.) and delete. Then highlight all others and use the right arrow between teh windows to send the backup to the phone.

Reboot.
Check settings, put in reg codes. Pull battery 30 seconds.... get a good charge and you're ready to go.