Adding Open Cart to site in Web Presence Builder

[Sumosami]

Help please ...someone, anyone lol ...I'm building a website & trying to add an open cart online shop instead of Ecwid ...can someone please explain in very plain language, maybe even step by step would be good, how to do this ...I am a complete novice but was determined to do this ...however I seem to be going round in circles at the mo ...I would really appreciate the help ...thanks