OK, then here is a summary about how to install solution plug-ins on managed endpoints:
1. Before solution plug-in installation rollout, you need to install SMA or ULM Agent on appropriate client computer (Windows OS or Unix, Linux, Mac OS)
2. When client computer has installed SMA or ULM Agent, then you can rollout a solution plug-in. Here is a list of available solution plug-in rollout policies in SMP Console (This list is for installed ITMS 7.5 SP1)
Open required solution plug-in rollout policy and enable it. Also you can modify default resource target of rollout policy, because default target will include there all available/applicable managed endpoints and install there solution plug-in.
3. If you want to make some managed endpoint server as Site Server, then you need to make sure that this server has IIS installed, then it will become as applicable to be a Site Server and you will be able to install there "Task Server" or "Package Server".
Go to Site Server Management page on SMP Console
Here you can add a managed server and make it as Site Server
Thanks,
IP.