How to replace screen on Prestigio Wize 3147 tablet

I bought a new glass touchscreen, I have unglued the edges of the broken screen using a hot air gun. The old screen is still attached by a ribbon cable at the top right corner, can't get to the fixing, maybe the display can be lifted out to get at the cable attachment? Or maybe get at it from the other side, via the wee door where the 2 sim cards are?? No obvious way to get it apart. Any suggestions? Thanks!! jake williams