Hey Allen,
Both Programs are very simple. Since you already have the Airbase.dat, half of the work is already done.
Both programs require you to set the Lat and Long. you will need to know the hight (alt of the ground above sea level) and heading of the runway.
Example:
This is the airbase.dat for Biggin Hill, as you can see. here is what you need to set up your runway.
[runway.6]
id=9007
name=*Biggin Hill
heading=77
allegiance=1
units_across=2
base_lat=N51 18.26
base_lon=E0 2.55
base_alt=505
takeoff_start_pos=-600,0
takeoff_stop_pos=1600,200
landing_start_pos=5000,350
landing_touchdown_pos=600,0
landing_stop_pos=-250,0
Depending on what program you want to use. this info will go into either the Header (FSSC) or project settings (groundmaker).
If you want to make a new one you can use google earth or mission builder to get the info you need.
I figured out both programs on my own. If you want a walkthrough i can do one up for you over the weekend.