Method 1 - ALL Carriers
This method requires that you already have a blackberry on your particular carrier. (or access to one).
1. Switch your SIM into your old device, Register on the network and push your servicebooks to ensure you have the latest (I used a T-Mobile 9700)
2. Go into options, advanced, servicebooks - HOLD THE ALT KEY and type SBEB. This will enable Legacy servicebook restore mode which allows you to backup/restore ALL of your servicebooks (and bypass having to use crackutil).
3. In Desktop Manager, plug in your 9700 (or whatever you used), go to backup-restore/advanced, on the right hand side select the servicebooks on your 9700 and press the “Left Arrow” to copy them to your PC. On the left hand side highlight the newly copied servicebooks, click file/save and name them something, 9800Servicebook for example, and save the file to the desktop. You’ve just made a COMPLETE BACKUP of your carriers servicebooks.
4. Switch your SIM back into the 9800, go to options/servicebooks, HOLD THE ALT KEY and type SBEB to enable Legacy SB restore mode.
5. Plug the 9800 into DM and restore the servicebooks that you just created using backup-restore/advanced.
6. Rebewt and bob’s ur uncle, working for all carriers. (if MMS is still tiny, it’s bc the 9800 isn’t identified on the network as a supported device).
IF YOU DECIDE TO MAKE YOUR SERVICEBOOK FILE PUBLIC FOR OTHER USERS, MAKE SURE YOU DELETE YOUR PERSONAL EMAIL SERVICEBOOKS BEFORE YOU MAKE THE BACKUP.
If you choose to then enable UMA follow my guide here.
Guide to enable UMA on an unlocked 9800 for T-Mobile
Unlocked Blackberry 9800 working on ALL gsm carriers