The fastest solution would be to install a horizon 5.x client that supports Virtual Printing.
https://customerconnect.vmware.com/en/downloads/info/slug/desktop_end_user_computing/vmware_horizon_...
the 8.x clients do not support Thinprint redirection (Virtual Printing) but do support the newer Integrated Printing feature. Alternatively your Horizon Admin can change the Horizon agent to use integrated printing.