Here's the poorboy version of the fork tool. Basically just a giant allen wrench used to hold the inner fork tube still while you back off the bolt in the bottom of your fork legs.
Nothing more than a piece of half inch copper water pipe bent on one end. A bolt with a 19mm head on it is inserted into the end of the tubing, then a hole for a fairly beefy cotter pin is drilled through both:
The fork tool is used to engage the socket in the head of the damper rod. Looks like this. You don't want to turn the rod with it. Just use it to keep the rod from spinning inside the fork leg while you undo the little allen bolt in the bottom of the fork leg. Your fork will literally fall apart once the bolt is out. That's right. One short little bolt is all that's keeping you from changing your fork seals in 20 seconds:
My welded version is made from a steel tube with bolts welded into both ends so I can just hold it with a ratchet. It's loaned out at the moment (actually it's been over a year. Bring it back. You know who you are). But you get the general idea.
If you commit to makling a welded-up version consider making it at least 2 feet long. Overkill for a TW but a lot of other forks with longer tubes share the 19mm hex and you'll be able to use it on a wide range of bikes. Obviously the guy in the video didn't have the tool. There's nothing necessarily wrong with his method, it's just a Rube Goldberg PITA compared to having the ability to pop the lower leg off. His seal driver is flippin' ingenius, but you won't need that, either.
I generally will break the fork caps and the bolt on the bottom of the tubes loose while the forks and front wheel are still on the bike. Saves a wrestling match when they're off the bike and and harder to handle. Putting them in a vise is an unnecessary risk which will often result in scarred fork tubes or lowers.
I've wanted to do a "How works the front fork" writeup, but I'm no draftsman. I found this page on the internet:
http://racetech.com/html_files/DampingRodForks.HTML
Some folks aren't terribly good with drawings or written explanations. But if you're remotely mechanically inclined while you have your forks apart, compare the drawings and written explanations with the actual hardware and try sliding the parts in and out to see how the pieces interact. The bell might go off in your head and you'll see how truly simple they are. Things like fork oil weight and fluid height may make a lot more sense when you have the hardware in your hands.
Upside-down forks, cartridge forks and emulators scare the hell out of most people. But once you realize that they don't function much differently than our simple damper rod forks (aside from the fact that you can change the size of the "holes" at will) you'll be an instant expert on those, as well. Fluid in, fluid out.
