First, you are going to need a bottle of Jack Daniel's. 😀
Next get a dremel with the smallest size bit you can find. You need to open up the tooth right in the middle on the side nearest your tongue. Be careful not to go too deep. You should pass through a white layer and then a yellow layer just until you see blood. Clean out as much of the gunk in this hollow part as you can; then fill it with bleach and let it sit for a few minutes.
You still with me? Now you are going to need some very thin, flexible files or serrated wire. If you haven't busted out the Jack Daniel's yet, now would be very good time to start. At the bottom of that hollow part you are going to find one or two little holes; these are the root canals. Thread the smallest wire into those little holes about... oh... probably 3/4 of an inch. Pull the wire in and out, in and out, until it moves without resistance. Clean the inside of the tooth again with bleach. Repeat the filing and bleach several times using a slightly larger wires each time. When you are done, you should see nothing but clean, yellow tooth down those little holes.
Now you need a piece of rubber that will fit well into those little holes that you cleaned. Once you find/create some rubber plugs that will fit all the way down the holes you need to roll them in a sealer. (I think the temporary filling stuff you can get from Walgreen's would work well for that.) So roll the rubber in the sealer and shove the rubber plugs into the holes. You will need to use a lot of pressure so find some metal instrument that is thin and strong enough to allow you to apply force down the holes.
Now for the finishing touches you are going to take a heavy duty needle (like the kind they use for yarn) and heat it up until it is glowing cherry red. Place that down the canal to melt the rubber and then, using the same instrument you used previously to pack the rubber, you are going to apply a lot of pressure inside the hole to force the rubber further down and into any side holes there might be. Do this once more just to be sure. Go ahead and clean up the tooth (we usually use chloroform for this, but if you can't get any, just use what you can find.).
If you've got any of that temporary filling material left over fill up the big hole in the top of the tooth and you're good to go. Be sure and take pictures throughout so you can share with your new buddies here on the student doctor network. And if you need any help during the procedure we'll be right here to answer any questions. Hope this helps.