Assuming you have obtained the c3560ipservicesk9mz1502se11.bin file, do not rush the installation. Failures are often due to skipped preparation.
However, because this model is End-of-Life (EOL), finding the download can be challenging. Here is a guide on where to find the file and how to upgrade your switch. What is c3560-ipservicesk9-mz.150-2.SE11.bin? 15.0(2)SE11 (Final/Long-Lived Release) Feature Set: IP Services (Advanced L3 Routing) File Type: (Image file) or (Archive, usually includes HTML for Web UI) Hardware Compatibility: c3560ipservicesk9mz1502se11bin download top
You must have a or a Cisco Login account with entitlement to the 3560 software. The official Cisco Software Download portal is: https://software.cisco.com/download/home/ Assuming you have obtained the c3560ipservicesk9mz1502se11