This method is intended for APAC releases, with 4.0.4 firmware out of the box, which in my case come out with P3100XXBLE3. Although these upgrade were intended for XSP and XME (Singapore and Malaysia) but actually APAC firmware are mostly the same, which also contain Bahasa Indonesia.
Notable upgrades: The major difference is that your tab will no longer in tablet mode but in Phablet mode just like Nexus 7. Well it's for you to decide which one is better.
WARNING!: There is a downside by upgrading with this method, that is your phone status will be "MODIFIED". Also you will need to WIPE your internal memory. Do BACKUP first!
Galaxy Tab 2 7.0" P3100 with P3100XXBLE3 firmware
3 OTA firmware files from sammobiles.com:
Make sure you already backup all the files, including files in internal memory.
Download all three required files and put it in MicroSD card of your tab.
Get into recovery mode. The method which work for me is:
turn off the tab,
then press power button,
AND hold volume up button RIGHT AFTER the power pressed.
If you successfully did the trick, you will enter recovery mode.
select apply update from external storage,
and select the OTA files on your microSD in following order
What it does exactly is
1. upgrading your P3100XXBLE3 to P3100XWBLF5
2. upgrading your P3100XWBLF5 to P3100XXBLH2
3. upgrading your P3100XXBLH2 to P3100XXCLI2 (Jelly Bean 4.1.1)
Do wipe data/Factory restore.
Well in my case, the first reboot is more likely stuck at Samsung logo.
So i did hard reset (press power button > 8 sec) then turn the tab on again, and voila it boots normally and welcome to Jelly Bean!