[Sony Xperia Miro, Tipo (Dual), J, E] allendelucas:
It did not work.

But I found something that I had not seen. By using Flashtool see the following message:

08/023/2013 09:23:45 - INFO - <- This level is successfully initialized

08/023/2013 09:23:45 - INFO - Flashtool Version 0.9.11.0 built on 2013-06-04 22:50:00

08/023/2013 09:23:49 - INFO - Device disconnected

08/023/2013 09:23:49 - INFO - Flash canceled

08/032/2013 09:32:02 - INFO - Selected ST26i / 11.0.A.3.28 / WE

08/032/2013 09:32:02 - INFO - Preparing files for flashing

08/032/2013 09:32:23 - INFO - Please connect your device into flashmode.

08/033/2013 09:33:16 - INFO - Device connected in flash mode

08/033/2013 09:33:17 - INFO - Opening device for R/W

08/033/2013 09:33:17 - INFO - Device connected in flash mode

08/033/2013 09:33:17 - INFO - Reading device information

08/033/2013 09:33:17 - INFO - Phone ready for flashmode operations.

08/033/2013 09:33:17 - INFO - Current device : ST26i - YT9105YUA0 - 1270-7015_R2E - 1263-8752_11.2.A.0.31 - WORLD-i_11.2.A.0.31

08/033/2013 09:33:17 - INFO - Start Flashing

08/033/2013 09:33:17 - INFO - Processing loader

08/033/2013 09:33:17 - INFO - Checking header

08/033/2013 09:33:18 - INFO - Flashing data

08/033/2013 09:33:21 - INFO - Loader : S1_Root_a8a4 - Version : R5D030 / Bootloader status : ROOTABLE

08/033/2013 09:33:22 - INFO - Processing partition-image.sin

08/033/2013 09:33:22 - INFO - Checking header

08/033/2013 09:33:22 - INFO - Flashing data

08/033/2013 09:33:23 - WARN - This file is ignored : simlock.ta

08/033/2013 09:33:23 - INFO - Processing kernel.sin

08/033/2013 09:33:23 - INFO - Checking header

08/033/2013 09:33:23 - INFO - Flashing data

08/033/2013 09:33:24 - INFO - Processing fota1.sin

08/033/2013 09:33:24 - INFO - Checking header

08/033/2013 09:33:24 - INFO - Flashing data

08/033/2013 09:33:24 - INFO - Processing fota0.sin

08/033/2013 09:33:24 - INFO - Checking header

08/033/2013 09:33:24 - INFO - Flashing data

08/033/2013 09:33:25 - INFO - Processing amss.sin

08/033/2013 09:33:25 - INFO - Checking header

08/033/2013 09:33:25 - INFO - Flashing data

08/033/2013 09:33:29 - INFO - Processing amss_fsg.sin

08/033/2013 09:33:29 - INFO - Checking header

08/033/2013 09:33:29 - INFO - Flashing data

08/033/2013 09:33:29 - INFO - Processing modem_fs2.sin

08/033/2013 09:33:29 - INFO - Checking header

08/033/2013 09:33:29 - INFO - Flashing data

08/033/2013 09:33:30 - INFO - Processing modem_fs1.sin

08/033/2013 09:33:30 - INFO - Checking header

08/033/2013 09:33:30 - INFO - Flashing data

08/033/2013 09:33:30 - INFO - Processing cache.sin

08/033/2013 09:33:30 - INFO - Checking header

08/033/2013 09:33:31 - INFO - Flashing data

08/033/2013 09:33:32 - INFO - Processing system.sin

08/033/2013 09:33:32 - INFO - Checking header

08/033/2013 09:33:32 - INFO - Flashing data

08/035/2013 09:35:32 - INFO - Processing userdata.sin

08/035/2013 09:35:33 - INFO - Checking header

08/035/2013 09:35:33 - INFO - Flashing data

08/035/2013 09:35:36 - INFO - Ending flash session

08/035/2013 09:35:36 - INFO - Flashing finished.

08/035/2013 09:35:36 - INFO - Please unplug and start your phone

08/035/2013 09:35:36 - INFO - For flashtool, Unknown Sources and Debugging must be checked in phone settings

08/035/2013 09:35:37 - INFO - Device connected in flash mode

08/035/2013 09:35:58 - INFO - Device disconnected

how can i change the baseband?