I know this topic is old but I I'll reply so it might help someone in future as I came across this when was looking for info.
So the instructions admin was writing about is here http://bbs.blackview.hk/viewtopic.php?t=2803
However this method seems complicated and there is much faster why.
Assuming you are starting from scratch and never used flash tool on your phone follow these instrutions:
1) download and install MTK drivers
. There is a lot of those on the internet. The package tested and used by me is here https://androidmtk.com/download-mtk-usb-all-drivers
You just have to download and install, no mumble jumble like in those instructions from admin
2) download and unpack SP Flash Tool
. Again you can use download links from previous webpage https://androidmtk.com/smart-phone-flash-tool
3) download ROM. Unpack it
. Currently the link for the newest is in this topic: http://bbs.blackview.hk/viewtopic.php?f=122&t=33087
4) Run Flash Tool.
. It should take you directly to Download page. Choose scatter file - it is in the rom package you downloaded and extracted. In my case the file was named "MT6735M_Android_scatter.txt".
NOW IF YOU GET CHECKSUM ERROR - delete Checksum.ini file form the ROM folder and try again.
5) Prepare your phone
. Take of battery prepare your usb cable. DO NOT CONNECT YOUR PHONE YET.
6) In flash tool click Download
7) connect your phone with usb cable
. The battery is out of your phone at this stage. the flashing process should start now.
8) Wait until Flashing process ends
. A green image should appear at the end.
9) close Flash Tool, Disconnect your phone. Assemble your phone and turn it on.
10) Wait for few minutes as the first boot after flash takes a lot of time. Congrats, you have new ROM!
You can check your version in device info, under compilation number. My says BV2000_B2_Blackview_20160526.
Remeber that you flash your phone on your own responsibility and there are chances you will brick your device.