To upgrade your wallet. Download the linux 64bit version from the electrum site.
https://download.electrum.org/3.1.0/Electrum-3.1.0.tar.gz <-put that in the browser and hit enter
then move that file from your tor persistence drive, to the the persistence folder and un compress it (extract it, right click and select extract). Once extracted, You'll see the new folder next to the old one. Then open the terminal: "applications" then "system tools" then terminal. Open the electrum folder (newer version) and find the file that says "electrum" (it's the 3rd file). click and hold it and then drag it to the open terminal. Then you'll see this in the terminal:
'/home/amnesia/Persistent/Electrum-3.1.0/Electrum-3.1.0/electrum' (or you can just select that text and paste it in the terminal if you upgrade to version 3.1.0)
Then hit enter.
The new electrum should load. Thats how you have to start it each time. The applications menu wont work, it will load the old one. You can delete the old folder. Don't worry your wallets are filed in another folder.
3.1.0 has some new features, the one I like the most is that it shows how many bytes your transaction is before filling out the miners fee. release notes here
Now for the segwit guide: click here for lower fees using segwit
or wait until march 13th when the new tails will be available including the new electrum