How to undo last upate 314 for SGP511?

[Kovikshamn]

After last update to 17.1.2.A.0.314 my wifi don't connect to network anymore. Problem is as discibed here: /t5/Xperia-Z2-Tablet/Z2-tablet-wifi-issue/td-p/798697/jump-to/first-unread-message

But, until problem is solved in latest version of software I like to go back to early version,, is that possible?

Great thanks for your respond  /K

[Thommo]

You will need to download a .ftf firmware file and manually flash this using Flashtools