How to Downgrade 3Gs from 4.3.5 to 4.3.3 for repair No service

For downgrade 3Gs from 4.3.5 to 4.3.3 we need to Download:

1- 3Gs 4.3.3 firmware from Here
2- Ireb4 from Here
3- Tiny Umbrella from Here
4- Snow Breeze 2.7 from Here
Now after download all Follow these step,s
1- Run Tiny software and connect Tethered jailbreak 3gs on ver 4.3.5 and save SHSH files, software should save shsh files for 4.3.5, 4.3.4, 4.3.3, 4.1 ver.
2- Now run Snow breeze and select 4.3.3 firmware and make custom restore firmware for 3Gs ver 4.3.3.it should paced on your computer desktop.
3- Now run IREB4 software and select iphone 3Gs and follow software instruction,s in the end your phone in DFU mode.
4- Run itunes software and Tiny umbrella software and start TSS server on Tiny Umbrella, your Itune should close automatically, that mean TSS server is working now.
5- Run ITUNES software again and restore your 3GS whith SHIFT+Restore 4.3.3 Firmware ver.
6- Itune take some time and your phone should restore to 4.3.3 downgrade ver from 4.3.5 ver.
7- Due to Custome restore file your phone complete on in Jailbreak condition.
8- Now run Cydia whith wifi and install repo666 application for signal repair.
That,s it now your phone in Untethered jailbreak condition whith full signal.