Switching to Agent-Based Monitoring

We are currently using the traditional config based icinga (without director) and all checks are executed via SSH.
We have 1 Master Node and 5 Satellites and about 200 Hosts to monitor.

The plan is to migrate all the SSH based checks to agent based monitoring
My first question is, if anyone can link me the installation script to rollout the agent, i had it once but cant find it anymore
and second … is there a way to migrate checks “on the fly” to agent based monitoring?