D2 Pad Rooting and Google Play

i have the D2-713g_bk version. it has google play already and im attempting to root it...i heard it might be pre-rooted so i installed Supersu but it says the binary is not installed and supersu cant install it. there are a few different versions listed here but i dont see which is best for this version. i dont want to follow something and brick the tablet. im trying to root so i can do the internal/external swap so it can have more space for apps (i only have 1 gig of useable space)

any guidance would be great.
NOTE: i can get into recovery but this version does NOT have a physical volume rocker... thanks in advance
 
most older android's come with the mobile market and its very easy so get google play store i did if several times for my late husbands phone go to google search and type in how to download google play for android and with will give you a bunch of different choices look for the one that is a video of someone holding a phone pay close att. or do it from a different device so you can follow the steps and walla there you have it its very easy i promise
 
Try Kingo Android Root for Windows. I just used it on my D2-712 and it worked flawlessly. The D2 is pretty hard to root normally. Google Kingo Android Root by KingoApp.