Your question is quite open-ended... How to install the spiral blade...

 

First of all, up vs down:  hold one end of the blade in one hand and run your finger(s) up and down the spiral blade... in one direction it is somewhat smooth cuz you're going with the teeth and the other direction is not smooth cuz you're going against the teeth... like all scrollsaw blades, it is correctly installed with the teeth pointing down... so the 'up' end is the beginning of the 'smooth' direction.

 

Second... these blades were designed by the devil and thus are twisted so that when held by the upper blade holder, the blade just willnot/cannot be held by the lower blade holder cuz it is twisted 90 degrees to what you need.  That's why you need two pliers at the table.  Hold the blade about an inch from the end and use the other pliers to untwist the end of the blade.  It's a little 'hit and miss' so you might have to fine tune it.  As others have said, an alternative is to buy spirals with flat ends... I'm only aware of Flying Dutchman making these. (BTW, other folks have attributed the design of spiral blades to the Forces of the Dark Side ala Star Wars... but it's essentially the same thing.)

 

Spence