Since this is my first tutorial, I am asking xda-developers' seniors' permission to post this.
I managed to root and install ROM on my P780, and I notice that there is no simple tutorial to root or/and install CWM and ROMs, so I thought why don't I do my own simple tutorial, especially for beginners like me?
Actually, rooting is simple for this phone. I used Framaroot for my phone. Thanks to Alephzain (search Alephzain framaroot in xda-developers forum). Just download Framaroot 1.6.1 from his tutorial, install it, and follow the instruction. Simple.
I know there's a lot of easy ways out there, but I used Mobileuncle for mine. Open PlayStore, search for Mobileuncle MTK Tools, download, install. You can get many CWM 6.1 img type out there for P780 (sorry I'm denied to post links), put it inside your SDcard. Then, open Mobile uncle, tap Recovery update, find your img file name. To find out there's CWM installed, just reboot to CWM when finished, or press volume up + volume down + power button when phone turned off.
I managed to find many available roms in needrom site. Some use CWM and some use Flashtool. I don't know, but I failed all ROMs that use CWM, so I'll tell you how to use Flash tool.
First, download flashtool and MTK drivers on your PC (I use Windows 7). Then, download your desired ROMs or stock ROM. There are direct links in the needrom site. Just register to see the links.
Install MTK drivers first. Then run Flashtool. click scatter-loading. Find MT6589_Android_scatter_emmc.txt in the downloaded ROM folder. Make sure DA DL All With Check Sum box is checked. Click firmware upgrade. Turn off phone. Connect via USB.
Wait until finished. (Green Circle Pop Up Window). Done. Restart phone.
Hope it helps. Press thank if I helped.