I got a D3 yesterday after being on the D1 for the last two years. So I got very familiar with theming various APK's on my D1. Is the process of cracking open an APK with 7Zip, dropping in your new PNG files, then pushing to the Droid the same on the D3 as the D1. This is how I would get my new framweork-res.apk on the D1 in the past...

Boot into recovery
Mount System
Open command prompt on computer and typ the following commands
adb push framework-res.apk /system/framework /framework-res.apk
adb shell "/system/bin/chmod 644 /system/framework /framework-res.apk"
Unmount System
adb reboot

Will that still work?