USE AT YOUR OWN RISK (use linux, on windows try cygwin maybe?)
you might have to install some dependencies during the process. For python-stuff this can usually be done with "easy_install
first install python-trezor lib. Open a shell (terminal) and do this: (don't enter '#>', that's the prompt). If you get "command not found" or similar, make sure you have git and python installed.
#> git clone https://github.com/trezor/python-trezor.git
#> cd python-trezor
#> sudo python2 setup.py install
#> cd ..
now get electrum sources from github and start electrum
#> git clone git://github.com/spesmilo/electrum
#> cd electrum
#> python2 electrum
It might tell you something about using pycc or something to generate icons. Just copy the line it tells you to execute and paste it into your shell and hit enter.
Now in electrum, go to tools -> plugins and enable the trezor plugin. Not sure if you need to restart electrum at that point. Might be necessary.
Then go to file -> new and setup a new wallet file by entering a name for the wallet file, check "hardware wallet", then "trezor" and follow instructions.
I also suggest you go to Tools -> Preferences and check "show transaction before broadcast", that way you can double-check transactions before broadcasting them.
BE CAREFUL, this is the development branch of electrum. Act accordingly and manage expectations. I've been using this for a couple of weeks now without major issues (well, I ran into one, but that's fixed thanks to stick and ThomasV)
Hopefully someone will find this helpful.
hope you can fix the bug soon. 
