This instructions is for a XL Sukkah/10x20
This Sukkah Might come in 2 boxes & a small bag with extra parts (i.e. its 2 small 10x10 sukkah)
& all you will need to do is use the parts as per the instructions which are needed for a 10x20 & the rest you can either throw out. Or keep them to have extra spare parts.
Instructions - click here
Below is a video of building the sukkah, however it is NOT the size you are building(10x20)