This may not be the "proper" way but it has worked on both my passenger side and now the driver side. And I can do them in about 15 mins.
I guess the motors in them just get weak and won't lock or unlock the door. When I opened the old ones up no gears were broke and it all looked good.
Step 1: Gather Tools
Looooooong straight blade screwdriver
Small straight blade screwdriver
Oh, and the replacement actuator.
Make sure to roll the window to the UP position too.
Step 2: Removal of Door Panel, Screw #1
You can see the clip and tab in the next photo.
Once you get the bezel out remove the phillips screw
Step 3: Removal of Door Panel, Screw #2
Once removed, remove the phillips screw shown.
Step 4: Removal of Door Panel, Switch Panel
This may be a good time to tell you to disconnect the battery since you are working on electronics.
Step 5: Remove Door Panel
That is all, just lift up. No prying, pulling snapping etc ... just lift straight up and pull out and it will come off.
Step 6: Getting to the Actuator
Remove the bolt shown to let the window guide rail move to get more room around the actuator.
There it is. Use the long screwdriver to release the power connector without breaking the tab off.
Step 7: Remove and Replace the Old Actuator
After looking at the new actuator and seeing how it attached, I decided to just pry and snap the old one out. Hey it's already not working, if the mounting tab gets broke, oh well.
Just make sure you don't put so much force you bend the metal mounts.
If you look at the actuator you will see it is slid up against a metal plate. Slide the looooong screwdriver in there and start prying it out. Take your time and work it out little by little, eventually the tab will snap and the actuator will almost fall off its mounting rail.
Once you get it out you will understand how it mounts.
I just plugged the connector into the new one and slid it in on the rail until I felt a click and it was snug up against the metal plate.
Also make sure the pin goes into the proper location.
At this point I also plugged in the switch and tested it's operation.
Step 8: Put It Back Together.
I also like to bend the clips back out a bit as I hate when trim rattles.
Also don't forget to put the window guide bolt back in ... I did and had to take it all back apart.