If you wish to use command prompt to install your SEPC redistributable package, you can do so with the command line in this article. This command will couple the msi and mst package together making them usable for your deployment.
Be sure to run this from a command prompt with administrator (elevated) privileges, and either run it from the directory where the files reside or specify the path as in the second example:
Example 1 (from path containing the downloaded MSI & MST) msiexec.exe /i "SEPCDeployment.msi" TRANSFORMS="SEPCDeployment.mst" /l*v log.log
Example 2 (pointing to directory containing MSI & MST) msiexec.exe /i "<SEPCDeployment.msi>" TRANSFORMS="<SEPCDeployment.mst>" /l*v