[HD2 General] T-Macgnolia:
Ok let me see if I can walk you through this some. First download the 02.04.12 HD2O© ROM, the AmeriCanAndroid AOSP HD2 SD card build, the Leo_RADIO_2.15.50.14, the EASEUS ALL-IN-ONE Partition Manager Software mentioned in the guide I linked, and if you do not already have it download the HD2 NAND Toolkit. You will also need to download and install Active Sync or Windows Mobile Device Center (these programs have the USB drivers you will need) depending on what version of Windows you have, you will just have to google for a download as I do not know what version of windows you have, I suggest you put both the WP7 ROM, the Android SD card build, and the 2.15.50.14 Radio in a folder that you can easily remember were they are on your computer. Also go ahead and install both the HD2 Toolkit and the partitioning software on your computer.

Now to make sure you do not have any problems with your SD card I recommend you do a full re-format of your SD card. You will need a USB card reader and a Micro SD card adapter.I linked them just so you will have a visual reference of what you need, but those are the ones I have and they work great. Aslo if your computer has a card reader you like mine does you just need a Micro SD card adapter. Now back to re-formatting your SD card.

Place your SD card in the Micro SD card adapter, then place the Micro SD card adapter in the USB card reader (or the USB card reader on your computer), and then plug the USB card reader into one of the USB ports on your computer. Let your computer install the drivers and go to the windows start menu and click on Computer or My computer depending on which version of Windows you are using. You should see the SD card as a removable drive. Right click the drive and select copy and then create a folder to paste the data that is on the SD card already so you will have a backup. Now right click on the drive again and select format, when the format window pops up make sure to uncheck the the box beside Quick Format and also make sure it says FAT32 under File System. Click Start and then click Ok on the warning window that pops up. Then set back and relax until the card is done being formatted.

Now you need to make sure you have at least 50% or more battery, but I suggest you have a full charge before you start just to be safe. Once you have the proper battery level you need to boot your HD2 into the bootloader by holding the volume down button down while you power on your HD2. When you see the multicolor boot connect it via USB and wait until you see the Serial in the white bar of the bootloader change to USB. Now open the folder with the 2.15.50.14 Radio in it and extract the files from the .rar file, you will need Win RAR to do this. Once you have the files extracted click on the CustomRUU.exe file and follow all of the on screen instructions. Once the RUU is done you will have the 2.15.50.14 Radio installed on your HD2.

Next you need to boot your HD2 back into the bootloader and connect it to your computer via USB again. Open the HD2NAND Toolkit and click on the Install HSPL button under Main Tools. Follow the on screen instructions and when it is done you will have HSPL 2.08 installed on your HD2. Now go back to the HD2 NAND Toolkit and click on the Insatall MAGLDR button under Main Tools. Follow the on screen instructions and when it is done you will have MAGLDR 1.13 installed on your HD2.

Now that you have MAGLDR installed on your HD2 it should only boot up to the MAGLDR 1.13 main menu. Go to option number 5 USB Flasher and then find the HD2O ROM file you downloaded and extract the files drom it. Once the files are extracted click on the DWI.exe and follow the on screen commands. When it is done you will have Windows Phone 7 on your HD2.

Now you need to follow the part of the guide you linked that I have quoted below. I left the link to the video of the method that I have quoted so watch it as it is a very good video. Oh and in case you do not notice it in the video, you need to hold down the power button while your HD2 is booting to boot to the MAGLDR main menu. And the video will show you how to get the Android build to boot on your HD2.

Hope this is detailed enough for you.