From the Crossfire manual:

The counter can also be reset by any individual after the indicated
service has been performed. To do so:
1. Turn the key to the ON/RUN position.
2. Within one second press the ****/button to the left of the display twice.
3. The present status for days remaining or distance traveled is displayed. Within ten seconds turn the key to OFF.
4. Press and hold the ****/button to the left of the display, while turning the key to ON/RUN again. The present
status for days remaining or distance traveled is displayed once more. Continue to hold the ****/button to the
left of the display.
After approximately ten seconds, a tone sounds and the display shows 7,000 miles for approximately
ten seconds.
5. Release the ****/button to the left of the display.

I use a Mityvac 7201. Advantage is it holds 8+ liters of oil and is translucent. Works great.