first , install driver for mtk .
1 . backup your data in phone
2. open flash tools ( right mouse –> run administrator )
3 . click to : scatter-loading and find file MT6582_Android_scatter_emmc.txt in lenovo rom folder .
4. click to : DA DL ALL with check sum and press to firmware->upgrade .
– Connect the USB cable to the program realize USB driver (DT must remove the battery shutdown, cases do not recognize the device and insert the battery and try again).
5 . Wait FlashTool running back will be notified that you have been out OK successfully Up Rom.
done . goodluck .
you can find stockrom for lenovo in here