How to open the back

I tried but got stuck. May u pls guide me bcos the lg tv was just manufactured last year in Poland oct. 2016. The model no is 32lh5iou-zc with s/n 610mace7w851. I am having problems with colored dotted vertical lines making viewing bad. What might be the problem? I wanted to open and resit the flexes and see whether the problem might go. There is warranty which hasn't expire. Unfortunately I am in Ghana, West Africa the warranty void. I need help. Thanks.