[Streak 5 Android Development] homeiss:
To write this I have basically pulled together all of the most pertinent information about upgrading and downgrading the streak into one big guide. Enjoy!

I would like to thank everyone who wrote guides that helped me with upgrading and downgrading my Streak.

If you are just getting started with the Streak, please read the What you need to know about the Dell Streak guide. Amongst other things this guide will show you how to set up fastboot and how to use it, which is essential for these guides. It's very easy to follow and has pictures! :) (Thanks Radddogg!)

READ EVERYTHING VERY CAREFULLY! THE GUIDES AND ALL FILES BELOW ARE USED AT YOUR OWN RISK!

Make sure you have over 80% battery life before you do these guides!

Table of Contents

Starting from AT&T 1.6 (build 6601)

Starting from O2 1.6 (build 4399)

Upgrading from O2 2.1 (build 8105) to Stephen Hyde's 2.2

Downgrade from Stephen Hyde's 2.2 to O2 2.1 (build 8105) & Downgrade from O2 2.1 (build 8105) to O2 1.6 (build 4399) then to AT&T 1.6 (build 6601) with Baseband Downgrade

Starting from AT&T 1.6 (build 6601)

You do not need to root your streak to upgrade to O2 2.1 so if that's you just skip to the Upgrading from AT&T 1.6 (build 6601) to O2 2.1 (build 8105) section. If you are not planing on upgrading but would like root access, you will need to unlock the Unknown Sources setting first.

Unlock Unknown Sources:

Open the phone dialer and type: *#*#307#*#* (the screen will flash and seem like nothing happened)

Go to the app drawer, you will now see EMList, open it (if it doesn't show up try a reboot).

Scrool down and select app_security

Select update unknown resource property to enable it

Go back to home screen and go Menu > Settings > Applications > then select Unknown Sources. To remove the EMList application, go back into the dialer and type: *#*#308#*#* After a reboot the EMList icon will be gone from your app drawer.

Gaining root access:

Download Universal Androot and install it.

Open it up and select Superuser for Android 1.5/1.6 in the drop down menu.

Tap on Go Root, after a few seconds it will tell you it was successful. If it fails the first time tap it again and it should work.

With the Universal Androot app you can unroot at any time by opening the app up and selecting the Undo Root button.

Upgrading from AT&T 1.6 (build 6601) to O2 2.1 (build 8105)

To go from AT&T 1.6 (build 6601) we need to go to O2 1.6 (build 4399) and then upgrade to O2 2.1 (build 8105).

Download the stock recovery ROM from the first post in this thread and the official Dell ROM from here.

Rename the Dell ROM Update.pkg and copy it to the root of your microsd.

Put the recovery image you downloaded into the same folder as the fastboot.exe.

Turn off the Streak and put it in fastboot mode by holding down the camera shutter button then press and hold the power button until a white screen comes up.

Tap on the Fastboot button in the top right corner.

You will see Wait for USB Fastboot detect, wait 10 seconds and then plug in the usb cable from the computer.

The screen will then change to say Fastboot_Mode. In windows go to Start > Run... > type: cmd and hit enter.

Now navagate to the fastboot.exe file with the cd command.

When you get there type: fastboot -i 0x413c flash recovery recovery.stock.img

When it says Download RECOVERY Done! on the Streak pull the battery and remove the usb cable.

Put the battery back in and hold the volume up and down buttons down while pressing the power button, it will boot into recovery menu.

Select Software upgrade via Update.pkg on SD Card using volume keys and camera button to select. Be patient it will take a while.

The Streak will reboot and you are now on O2 1.6 (build 4399).

Now your AT&T Streak is on the same build and version of Android as the original UK O2 Streak. If you've made it this far upgrading to 2.1 is a piece of cake.

Download the O2 2.1 (build 8105) file in this post.

Rename the file to Update.pkg and copy it over the old file in the root of your microsd.

Turn of the Streak.

Hold the volume up and down buttons down while pressing the power button, it will boot back into recovery. Be patient it will take a while.

Select Software upgrade via Update.pkg on SD Card using volume keys and camera button to select. Be patient it will take a while.

The Streak will reboot and you are now on O2 2.1 (build 8105).

You can use Universal Androot to gain root like above only select Superuser for Android 2.0 ~ 2.2. It will say it failed but if you do it again it will work.

Original sources: here & here