[Samsung Galaxy Nexus] locomain:
TUTORIAL

here we go! i will try and make this as clear as possible:)

1. plug in your phone

2. adb pull /system/app/SystemUI.apk

3. make a copy and keep it somewhere save(need this later)

4. decompile SystemUI.apk

5. browse your way to /res/layout/status_bar_tracker and open the file

you will see a lot of code

change the lines in your systemui to the red lines in the code below

<?xml version="1.0" encoding="utf-8"?>
<com.android.systemui.statusbar.phone.TrackingView android:orientation="vertical" [COLOR="red"]android:background="@drawable/pulldown" [/COLOR]android:paddingLeft="0.0px" android:paddingRight="0.0px" android:paddingBottom="0.0px" android:focusable="true" android:visibility="gone" android:descendantFocusability="afterDescendants"
xmlns:android="http://schemas.android.com/apk/res/android">
<FrameLayout [COLOR="Red"]android:background="@drawable/pulldown_background" [/COLOR]android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0">
<com.android.systemui.statusbar.policy.WeatherText android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="center" android:layout_gravity="bottom" android:paddingBottom="40.0dip" android:layout_width="fill_parent" android:layout_height="wrap_content" />
<com.android.systemui.statusbar.phone.CarrierLabel android:textAppearance="@style/TextAppearance.StatusBar.Clock" android:gravity="center" android:layout_gravity="bottom" android:paddingBottom="20.0dip" android:layout_width="fill_parent" android:layout_height="wrap_content" />
</FrameLayout>
<com.android.systemui.statusbar.phone.CloseDragHandle android:orientation="vertical" android:id="@id/close" android:background="#ee000000" android:layout_width="fill_parent" android:layout_height="wrap_content">
<ImageView android:layout_gravity="center" android:layout_width="fill_parent" android:layout_height="wrap_content" android:src="@drawable/status_bar_close_on" android:scaleType="fitCenter" />
</com.android.systemui.statusbar.phone.CloseDragHandle>
</com.android.systemui.statusbar.phone.TrackingView>

6.save and go to /res/drawable/

7.make an .xml file named pulldown.xml

8. open it and paste the code below inside and save

8a. the android:drawable lines represent the images of the animation

so make sure the name of the images and the lines are the same.

so in my case the first image is called

android:drawable="@drawable/pulldown_anim001"

and je can add or remove lines to match the number of images you are going to use

<?xml version="1.0" encoding="utf-8"?>
<animation-list android:oneshot="false"
xmlns:android="http://schemas.android.com/apk/res/android">
<item android:duration="150" android:drawable="@drawable/pulldown_anim001" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim002" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim003" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim004" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim005" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim006" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim007" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim008" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim009" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim010" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim011" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim012" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim013" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim014" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim015" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim016" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim017" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim018" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim019" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim020" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim021" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim022" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim023" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim024" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim025" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim026" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim027" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim028" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim029" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim030" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim031" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim032" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim033" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim034" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim035" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim036" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim037" />
<item android:duration="150" android:drawable="@drawable/pulldown_anim038" />

9. place your images you are going use in drawable-xhdpi

10. place this image in your drawable-xhdpi

11. save and compile your SystemUI

12. open your backup of the SystemUI apk and copy the res map and the resources.arsc of the just compiled apk into the backup

13. adb remount

14. adb push /system/app/

15. adb reboot

hope this is clear:)

this should work on every gnex rom