[A] Here are the steps
Yeah, it took me a week of digging to find this answer.
1. Proceed at your own risk and don't blame me if you brick your phone.
2. While I've done my best to document the steps I took, there's always a chance I've mistyped something.
3. If you're unsure at any point, STOP! Re-read everything so you fully understand what you're doing.
4. Editing .odex files can be extremely tricky! All it takes is a bad edit to royally screw up your phone.
This guide assumes:
* you have a Captivate and it's running stock Eclair. (Don't know about other phones or other OSes.)
* you have rooted your phone, and have busybox & Superuser Permissions installed.
* you have adb installed and working on a PC.
* you have baksmali and smali installed and working on a PC (along with Java).
* you have downloaded the utility "dexopt-wrapper". (Do a search - you'll find it.)
* you know what the BOOTCLASSPATH value is for your phone. (Hint: It's in /init.rc)
* you have made a complete backup of your phone! (Yes, if something goes wrong, it's much nicer to be able to restore files from a recent backup than to have to wipe the phone and start from scratch again.)
- I highly recommend you install ROM Manager w/ ClockworkMod. (And don't delete /sdcard/update.zip)
When you see a line beginning with >, that's a command to be executed on the PC.
When you see a line beginning with #, that's a command to be executed on the phone.
Ready? Here we go:
put the dexopt-wrapper onto your phone.
> adb push dexopt-wrapper /sdcard
copy all of the /system/framework files onto your PC.
> adb pull /system/framework
let's pretend you want to change something in services.odex.
decompile the .odex file
> baksmali -x services.odex -o services.out
now edit whatever .smali file you want in the services.out folder.
rebuild the classes.dex file for services.odex.
> smali -o classes.dex services.out
now put classes.dex into services.jar (I used WinRAR, but other ZIP utilities should work.)
put the new .jar file onto your phone.
> adb push services.jar /sdcard
> adb shell
become super user
put the dexopt-wrapper utility into the bin folder with the correct permissions. (you only need to do this once, obviously.)
# cd /system/bin
# busybox cp /sdcard/dexopt-wrapper .
# busybox chmod 755 dexopt-wrapper
# cd /sdcard
create a new .odex file from the new .jar file
# dexopt-wrapper services.jar new.odex [BOOTCLASSPATH]
yes, fill in the value of BOOTCLASSPATH, without the 
here's the "special sauce": copy over the "signature" from the current .odex file into the new .odex file. do NOT continue until this command succeeds!
hint: the file size of the new.odex file should not change!
# busybox dd if=/system/framework/services.odex of=new.odex bs=1 count=20 skip=52 seek=52 conv=notrunc
now replace the old .odex file with the new .odex file.
# cd /system/framework
# busybox cp /sdcard/new.odex services.odex
# busybox chmod 644 services.odex
and you're done.
Now, if all goes well, your phone should reboot normally.
However, if something has not gone well, you'll hear the bootup sounds, but the screen will be "stuck" on the first white logo screen. That means the new .odex file was not accepted. What to do? Well, first, (and with all do respect) Don't Panic! Plug in the USB line and issue:
> adb reboot recovery
That should drop you into the recovery. "Apply Updates" and that will get you into ClockworkMod. Then you can restore the /system files from your full backup (the one you did RIGHT BEFORE doing any of this, right?) and be back up and running in just a few minutes. (Yeah, I had to do this many times. It's scary the first time, but you get use to it after a while.)