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.
I followed all directions then went to enable the plugin. I can see the option there to enable trezor in the plugins list but it is grayed out and the checkbox cant be marked.
hmm. strange, it's grayed out for me, too. The checkbox is unmarked and can't be marked. However, the trezor still works. Can you try if it works?
I can confirm that it is now working. What I did was go to file/new and started a new hardware wallet, chose the trezor option with the trezor plugged in. The trezor wallet loaded up. I then went back to the plugin options and noticed that the trezor option was automatically checked and working on its own.