The location of the entrance gate is 106° 59' 2" W + 32° 59' 18" N. This should be good enough for your goto telescope.
From Las Cruces take I-25 to the Upham exit #32 and turn right. Continue 23 more miles. Halfway between mile marker 23 and 24 is the turn to the Spaceport which is another 1.5 miles to the east.
These pictures show the way. You can also use Google Maps.
This 5 minute video starts at I-25 at exit #9. Driving at 1200 m.p.h. You
end up at the Spaceport in 5 minutes.