if you want you can knock the neck off of it

What precautions do i need to make before taking it to a landfill?
are we actually driving to a landfill and disposing it, or just throwing it into a dumpster/garbage can for pickup?
unless you are doing it yourself i wouldn't want to leave it as is. if it's potentially going to be handled by someone else, discharge the tube and place it into a box and mark it glass. i would drop the box or knock the neck off to break the glass in a controlled manner so there is no surprise later on... if your driving it to a landfill and tossing it into a pile/giant dumpster... just toss it.
if they have electronics recycling there, just place it with that stuff. problem solved.