1) Obtain the Deodexed install from RootzWiki. Link in OP.
2) Extract the zip file (I downloaded mine to the PC and unzipped it there).
3) Open the extracted folder, then navigate to /system/app.
4) Locate the BlurEmail.apk file (not to be confused with blur_email.apk) and copy it.
5) Paste the file to the SD card or internal storage.
6) Using a file explorer (such as Root Explorer),copy the file from where you put it and paste to the /system/app directory (you may need to mount as RW first).
7) Set the permissions to rw-r--r-- by long-pressing and selecting "Permissions" (this is if you use Root Explorer, other programs may vary). Make sure owner has Read and Write, while Group and Others have Read only.
8) Reboot phone, and enjoy!
Edit: alternatively, you can adb push the file to /system/app. Will yield the same result.