The 'monitor.hex' file can be loaded into an empty chip using a device called a 'programmer'.

A popular programmer is the ICD2 obtainable from Microchip, of which
there are several cheaper clones available. One such clone is
manufactured by Olimex. This one is the most complete: it is supported
by Microchip in the MPLAB toolchain, and there are several open source
tools available that can use this programmer device. 

We suggest to use
the command line tool 'piklab-prog' which is bundled with !PikLab, an
open source MPLAB replacement.

There are a lot of cheaper and simpler alternatives to the ICD2. If you just need a programmer to get bootstrapped, consult your local PIC programming expert.

The CATkit board has a connector labeled ICD2. This is a standard
in-circuit programming connector, as used on the Olimex board, using 6
pins to connect the board to a programmer device.

[[Image(catkit_icd2-400x300.jpg, nolink, float:left)]]

As an illustration, this is the command line used to burn the monitor
using 'piklab-prog' (from a terminal, not the PURRR18 console):

{{{
piklab-prog -t usb -p icd2 --firmware-dir <FIRMWARE>  -d 18F1320 -c program monitor.hex
}}}

The parameter <FIRMARE> is the directory containing the Microchip ICD2
firmware, which is bundled with MPLAB.