SEP12.1.5

Hi

There are three files for SEP 12.1.5 for download

Symantec_Endpoint_Protection_12.1.5_Part1_Installation_EN.exe

Symantec_Endpoint_Protection_12.1.5_Part2_Tools_EN.exe

Symantec_Endpoint_Protection_12.1.5_SEPM_EN.exe

I want to upgrad my existing 12.1.x to 12.1.5

which file I have to use " 12.1.5_SEPM_EN.exe " or "12.1.5_Part1_Installation_EN  "

and what is difference between these two files

Thanks