trying to install HPLIP 3.16.5 on linuxmint distro 17.3

Selectied key item results running hp-check -t....

Status Types:
    OK
    MISSING - Missing Dependency or Permission or Plug-in
    INCOMPAT - Incompatible dependency-version or Plugin-version
 HPLIP CONFIGURATION |
-----------------------
HPLIP-Version: HPLIP 3.16.5
HPLIP-Home: /usr/share/hplip
HPLIP-Installation: Auto installation is supported for linuxmint distro17.3 version

[hplip]
version=3.16.5

HPOfficejetPro8500
------------------
Type: Unknown
Device URI: serial:/dev/ttyS0?baud=115200+bits=8+parity=+flow=none
PPD: /etc/cups/ppd/HPOfficejetPro8500.ppd
PPD Description: HP Officejet Pro 8500 a910, hpcups 3.15.2
Printer status: printer HPOfficejetPro8500 is idle. enabled since Wed 04 May 2016 02:51:24 PM PDT
warning: Printer is not HPLIP installed. Printers must use the hp: or hpfax: CUPS backend for HP-Devices.

Question:
How do I run hp: CUPS backend for HP-Devices. (I don't use the fax component).