We thank CamaroShifter85 for the permission to reproduce his tutorial here. This tutorial is based on the w810i, but should work on other phones that supports flash menus.
How to Get Flash menus via PhoneXS:
1. CHARGE YOUR PHONE!!! Even with a full battery, there are "chances" that your battery may die before it finishes flashing due to longer bruteforcing times (bruteforcing = trying to crack passwords by trying extreme amounts of combinations, or sometimes a set dictionary, in just a few seconds. This can be quick if the password is one of the first words selected, or longer if it's a tougher password to crack).
2. Take out your SIMS card along with your memory card (May not be needed, but it's always a smart idea because glitches DO happen. Also, make sure you have a bit of memory space on your phone left, you won't need more than 5-10 MB to get by safely, so no worries). Then download THIS . This .rar file is just a little pack of everything you're going to need to put these themes on, including a few extras.
3. Time for the trickier part. We need to update your USB drivers. If you've already previously updated them to flash them earlier with PhoneXS, then just skip this step. If you're still new to PhoneSX, then you will MOST LIKELY need to do this, though your USB drivers MAY be up to date.
To start, open the FlashThemes.rar file that I've supplied everyone in the above link and open up the USBFlashdriver folder, and drag/drop these two items into your "my documents" folder. They will just be their temporarily, don't worry. Now double click the Phone-XS V2 exe file and whenever it select "USB" for that's how you're going to send the files to your phone.
Here's the tricky part though. Click "Start" and the log that shows up should tell you take battery out.. hold C.. blah blah. Just make sure your phone is turned off, you took your SIMS card out, and you took your memory card out as well.
Then before connecting your phone to your computer via the USB cable, hold the "C" button ON YOUR PHONE! (not keyboard) and connect it to the USB, still holding the C button.
Now to install the USB drivers, right-click "My Computer" and click the "hardware" tab, followed by the "device manager" button. Down the list a bit, there should be an option that says "Other Devices" and it will say something like "unknown device" or "USB device". Whatever it is, if you don't have the USB driver.. it's unrecognized. I'm not POSITIVE what it says because I've gone through with it already, but in any case, rightclick it and click "Install (or update) Drivers". A window will come up asking if you want to install the driver automatically or manual (find the folder yourself). Check the second option (manually) and whenever it click the "Find directory manually" option, and where it has the "Browse" box.. simply tell it to browse under your "My Documents" folder. It should start and finish installing the drivers, and you're done with the hardest part of the tutorial.
Now you can delete those files you dropped into your "My Documents" folder if need be.
4. Now you will most likely have to exit out of Phone-XS, and re-run it again. This time through, do the whole same process above, except instead, as soon as you connect it (Make sure it's still off and you're holding down the "C" button while hooking it up), it should show up abuncha different actions on the log. Once finished, you'll know it's done. It only takes about 5 seconds or so..
5. Once there, it's time for you to decide what you want to upload. If you look back at the FlashThemes.rar directory, there will be 2 folders labeled "files_to_upload" and "Flash (Only Themes)". If you want the themes, and also an enhanced camera driver, along with the acoustic files that REALLY increased the volume of your phone (speakerphone and headset and all), then you won't have to do anything as far as modding files go. Also, the acoustic files don't sacrifice quality, so don't worry about that. The only reason that there quality may seem an issue is if you turn it up all the way, and that's because then my phone is louder than my TV, and such small speakers aren't meant for that kind of volume. If you keep the volume about half notch though, it's as good as a fully-volumed phone that DOESN'T have these acoustic files, and the same quality.
Note: IF YOU DON'T WANT THE CAM DRIVERS AND THE ACOUSTIC DRIVERS, RATHER ONLY THE THEMES, then delete the "files_to_upload" folder and rename the "Flash (Only Themes) folder to "files_to_upload".. for that's what PhoneXS will upload.
6. Once you have your preferences situated and the right name on the right folder, continue back to the PhoneXS application, and towards the bottom, click the FSX button, and it should open up a new screen.
From here, all you have to worry about doing is simply clicking the "Start FSX" and let PhoneSX do the rest! Keep in mind though, this can take JUST as much time as flashing, only without the problems having your phone not work if interrupted, so it's completely safe.
7. Once uploading the flash files (and other drivers if you wanted them), turn your phone back on and hook it up to your computer. Now just open up the "PHONE" directory (I use phone because I prefer putting major files like songs/videos on my cards) and open the "themes" folder. Just drag/drop all of the themes that are in "FlashThemes.rar/Themes" folder into the "themes" folder in your phone.
The next time you turn your phone on, you SHOULD have new working themes!!
Where to download more flash menus?
From the mobile9 gallery, go to flash download then search for Flash Menu. Alternatively, this is the direct link to all Sony Ericsson Flash Menus.