How to leave session in LogMeIn Rescue without ending session for collaborator?

Here is the scenario,

I am using LogMeIn Rescue version 7.12.3351 (64-bit)

1. Connected session with a customer.
2. I am level 1 technician. Cannot resolve the issue.
3. I invited level 2 technician.

Now I need to leave session without ending session for Level 2 technician. How would I do that?