Covered Litter Box or DIY myself from a Storage box?

[rougedeep]

My cat Marlet have been pooping outside the litter box. His body is inside the litter but it seems that he tend to pee and poop on the edge of the litter box, but the butt sometime just sticks out and he just let it off.

I read about replacing the litter box with a bigger one and i've already done that, brought one big plastic tray from ikea and accidents still repeat. I hate cleaning the poop on the floor so many times.

So im looking into DIYing it from a storage box , but i don't know how to cut a hole in the plastic..

Can a utility knife like my bf's army swiss knife be used to cut the plastic? I don't have any jigsaw tool at home. Or any suggestion if your cat faces such issues?