My 2007 Dodge cummins 6.7 is telling me to perform service and the catalyst is full. How do I fix this problem myself?

Intervention Regeneration Strategy - EVIC
Message Process Flow (Catalyst Full Message)
(6.7L Diesel Engines Only)

Your new Cummins 6.7L diesel meets all EPA Heavy
Duty Diesel Engine Emissions Standards, resulting in the
lowest emitting diesel engine ever produced.
To achieve these emission standards your vehicle is
equipped with state of the art engine and exhaust system.
The engine and exhaust aftertreatment system work
together to achieve the EPA Heavy Duty Diesel Engine
Emissions Standards. These systems are seamlessly integrated
into your vehicle and managed by the Cummins
6.7L engine Powertrain Control Module (PCM). The PCM
manages engine combustion to allow the exhaust system's
catalyst to trap and burn Particulate Matter (PM)
pollutants, with no input or interaction on your part.
Additionally, the overhead console in your vehicle has
the ability to alert you to additional maintenance required
on your truck or engine. Refer to the following
messages that may be displayed on your Electronic
Vehicle Information Center (EVIC):

WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your exhaust
system. Do not park or operate your vehicle in areas
where your exhaust system can contact anything that
can burn.

Perform Service
The 6.7L Cummins engine utilizes a Closed Crankcase
Ventilation (CCV) system, EGR Valve and a EGR Cooler.
This system filters and recycles gasses produced in the
crankcase during the normal combustion process. Perform
Service will be displayed on the overhead console of
your vehicle if the CCV filter, EGR Valve and EGR Cooler
is due for required maintenance. The CCV filter is located
on the top of the engine valve cover. For additional
information, see your local authorized dealer.
Catalyst Full See Owner Manual
Catalyst Full See Owner Manual will be displayed on the
overhead console of your vehicle if the exhaust particulate
filter reaches 80% of its maximum storage capacity.
Under conditions of exclusive short duration and low
speed driving cycles, your Cummins engine and exhaust
aftertreatment system may never reach the conditions
required to remove the trapped PM, if this occurs Catalyst
Full See Owner Manual will be displayed on the
overhead console in your vehicle. If this message is
displayed you will hear one chime to assist in alerting
you of this condition.
Catalyst Stat::::::::::80%
Catalyst Stat::::::::::80% will replace the message Catalyst
Full See Owner Manual after it is displayed for one
minute. The engine Powertrain Control Module (PCM)
will continue to monitor the amount of particulate matter
trapped in the particulate filter. This message indicates
the percentage of the particulate filter capacity that has
been used.

By simply driving your vehicle at highway speeds for as
little as 45 minutes you can remedy the condition in the
particulate filter system and allow your Cummins engine
and exhaust Aftertreatment system to remove the
trapped PM and restore the system to normal operating
condition.
Catalyst Stat:::::::::::80%, 90%, 99%
Catalyst Stat:::::::::::80%, 90%, 99% If you are unable to
drive your vehicle under these conditions for an extended
period of time after the initial warning notification,
the Engine PCM will continue to monitor the
particulate filter and will display the progression of
particulate filter usage (80, 90, 99%) on the EVIC message
center.

CATALYST FULL SERVICE REQD
If the particulate filter reaches 99% of it's capacity the
overhead console in your vehicle will chime twice and
display the message CATALYST FULL SERVICE REQD.
At this point the engine PCM will register a fault code,
the instrument panel will display a MIL light and the
engine PCM will derate the truck reducing its horsepower
and torque output.
The PCM derates the engine in order to limit the likelihood
of permanent damage to the aftertreatment system.
If this condition is not corrected and a dealer service is
not performed, extensive exhaust aftertreatment damage
can occur. In order to correct this condition it will be
necessary to have the truck serviced by your local
authorized dealer.