You have a Management Center (MC) device running 1.x version which is going End of Life (EoL) in June 2019 and you want to upgrade to 2.x code.
To upgrade from 1.x code to 2.x please follow these steps:
en
security ssl client-authentication disable
installed-systems add {http/s://x.x.x.x/path/to/file.bcsi}
restart reboot
NOTE: Refer to the attached release notes for more details.