What I do is the following:
(this assumes you have the Internet search widget enabled)
1.) press the right arrow key
a flashing text cursor is shown
2.) type anything and enter
MicroB pops up
if it didn't autoconnect to a saved network already then it will ask to connect to a wifi network. Connect or cancel (use left and right arrows and enter)
3.) press the home button (two squares)
the quick taskbar will pop-up.
4.) press left arrow key
the taskbar icon will be selected
5.) press up arrow key twice to select Applications menu
6.) right arrow key, now open something like terminal.
7.) to open another application simply repeat steps 3-6.
8.) ctrl+q to close a window


Alternatively if you didn't leave the search widget enabled you can try the following:
Requires:
* wired keyboard (or a wireless one that has a usb dongle; non-bt dongle)
* USB OTG adapter

Plug the OTG adapter into the N810. Plug the keyboard (or dongle) into the adapter. Press Alt+Tab to reach the quick taskbar menu and follow steps 4-6.

Now would be a good time to install openssh-server (from terminal with apt-get install), VNC server, fanoush's bootmenu w/ emergency ssh boot enabled.