That is once you figure out how it is run behind the dash and through the firewall (not sure if its the firewall or a seperate panel/ divider.
First thing is take off the vents/ grilles at bottom of windshield (exterior)
Remove 3 bolts holding the mast
Under the grille you removed is a grate looking thing, you will have to look in and you will see thebwire running through the firewall
Now back to the interior, you will notice the antenna wire runs in a cable run behind the dash. What i did was reached my hand up and felt around a bit. The antenna wire has a plug at the end of the run in the dash, you just disconnect thins by pulling. Now be careful, there are two wires ones the antenna, one im not sure what it is. I knew i had the right one because it has about six inches and then runs through a grommet through the firewall.
Once diconnected, you have to push the cable through the firewall by grabbing half inch behind the grommet and pushing towards the engine. It will only go forward, it will not come in to the passenger compartment.
Now it should be free, just pull the mast and the cable will come with it.
To reinstall put the cable in the hole and set the mast where it should be, reach in where you removed the grate/ grill and the antenna wire feeds back in about six inches from the end of the grate towards the passenger side.
Make sure the grommet is in right, if not you will have water/ mold issues.
This is on a 95 astro work van, i just got it this week, i was tired of beating up my car at work. Alot of this work you are doing by feel, if you could see everything it would take 5 minutes. I will try to make a DIY with pics when i get a chance.
Thanks for all the help the boards have given me and i look forward to becoming an active member, i have 1 and a half door handles to do soon!
BTW, i used The White House as my name because that is what i named my van. ( i got it from a book)