Download the CM10 Preview build ROM zip from HERE. Save the file on your PC. Download the GApps zip file for Jelly Bean from HERE. Make sure to download the file for Jelly Bean and not the other one. Save it on your PC and this file will help you flash the Play Store, Google Now, Gmail, Gtalk and all other Google apps, that you need to use in order to take control over your P1000 tablet. Move both files on your device’s internal sdcard. Do not extract their contents. After the transfer is complete you should disconnect the phone from your PC and power it OFF. Boot into CWM Recovery by pressing and holding simultaneously ‘volume up’ + ‘power’ buttons until the tablet’s screen powers on. When in ClockworkMod Recovery you should first select ‘wipe data/ factory reset’ and confirm the action. Next, select ‘install zip from sdcard’ and then, from the next recovery screen select ‘choose zip from sdcard’. Point to the CM10 ROM build and confirm that you want to install it. After the ROM has been installed you will have to repeat step 6 but, this time you have to install the GApps file the same way you did with the CM10 Preview build. When the ROM installation is complete you will have to return to the main recovery menu and select ‘reboot system now’. Now the first boot process into Jelly Bean CM10 alpha ROM will be started and this will take at least 5 minutes to complete. Wait until all files are loaded and when you’re asked, enter the Google account details to take control over your tablet. That’s all the info you needed to flash this new ROM and now you should start testing it.
Full Original Source for Upgrade Download all Here !