How do you replace the front turn signal bulb located on a 1995 Ford Aerostar XL?
Remove the headlight door (that is the chrome trim around the headlight/parking-turn lens) to gain access to the bulb. You may need to push down on the bumper to get to the bottom screw. Once you have access just push and twist the bulb to remove.
I just changed a turn signal bulb in my 2001 330xi. I found the answer on Wiki. Look for the question "How do you replace the front turn signal bulb located on a 2000 BMW 323?" Same design. And, surprisingly, very easy to change. Should be similar to this: http://m3.madrussian.net/diy_front_turnsignal.shtml
I'm not sure about the 2001, but on a '97, under the hood there are 2 inverted "L" shaped slide clips near the front corners. These pull straight up and allow you to pull out the headlight/turn signal unit. Twist the turn signal housing 1/4 turn CCW to expose the bulb and replace. Or, take it to the dealer and let them do it.
Simply by removing the front signal lense, First pop the hood open. Secondly, locate the front signal lense. Third, their is a screw on the top of the lense, unscrew it, pull the lense toward the front, than twist the light socket, replace the bulb. For reinstallion just work backwards. Good luck :)