Using assign on ui designer with API PUT method

Hi

i'm a intern on a company, and i couldn't find any answer on want can i do or not with the bonita studio api on a web designer page, since i not very skill on javascript and still learning coding.

I was wondering if it is possible to a reassign of a task through a update api, and if its possible whats the best way to do it, and if possible too the steps to take through all the process of making it. 

thanks for your time and have a good day :)