I made some pictures about the installation process. You can also check this slideshow: http://lillin.hu/kepek/110_boosterplug/index.html.
Remove the gas tank and identify the temperature sensor on top left side of the air box. All the directions are given as if you would sit on the bike.
Drill a 3mm hole on the fin found on the front side of the airbox.
Drill two 3mm holes on the fins found on the left side of the airbox. Note the position of the holes close to the corner of the fins.
Disconect the air temperature sensor's plug.
Route a zip tie through the holes and around the connector as shown here.
Same from the opposite side.
Secure the connector with the zip tie to the airbox body. The zip tie will nicely fit into the collar of the connector.
Pick up your Booster Plug and place it such that you see the inscription.
Apply double sided adhesive tape on the Booster Plug body.
Attach the Booster Plug connector to the temperature sensor on the airbox.
Attach the other Booster Plug connector to the connector that you just fixed to the airbox body with a zip tie.
Peel off the other side of the double sided adhesive tape and fix the Booster Plug on the front sidewall of the airbox body such that the cables should be neither loose nor tight.
Same from another perspective.
Zip tie the third (longest) cable of the Booster Plug to the hole you drilled on the front fin.
Zip tie the long cable along the brake line such that the temperature sensor is attached to the brake line fixture's gutter. Allow the temperature sensor to protrude from the brake line fixture into free air.
Reinstall the gas tank. You will still see the connector on the left side of the airbox.
Finally inspect once again the Booster Plug air temperature sensor. It should be appropriately fixed and it should protrude into free air.