SCCM Server Update Guide
here is a good article on how to upgrade SCCM server: https://www.systemcenterdudes.com/step-by-step-sccm-2012-r2-sp1-cu3-installation-guide/ https://support.microsoft.com/en-us/kb/3135680
here is a good article on how to upgrade SCCM server: https://www.systemcenterdudes.com/step-by-step-sccm-2012-r2-sp1-cu3-installation-guide/ https://support.microsoft.com/en-us/kb/3135680