Select the issue as usual and choose "Allocate to Landlord"

If the landlord is already associated with the property their details will appear.  If not, you can add them to the system by typing their email address into the text box that appears.

You can then type in a message to the landlord and click "Proceed to next step". This will send them an email asking them to carry out the job:

The issue is then progressed much like when a contractor is assigned a job through "Instruct Works".