OPT Change of employment and extension

[aneesh158]

Hello experts,

                        I am currently on my F1 OPT EAD working for employer A and want to work for and file for my OPT extension with Employer B. Can I change the employer on OPT just by updating the university and USCIS or is there any other process and what all documents do i need to submit while applying for 24-months OPT STEM Extension.

Do i need to submit documents related to previous employer such as paystubs of my previous employer.

or 

Submitting information and documents related to new employer(who is filing for opt extension) is enough?