Hey there guys!
So, I've been looking around for quite some time, trying to figure out how to install shaders on Tekkit Classic, and I really couldn't find any proper tutorials. I've finally succeeded yesterday, and decided to make a quick tutorial on how it works. So, without further ado, I show you, a proper tutorial on how to install SEUS on Tekkit Classic! As simplistic as it gets! (You'll also get TreeCapitator, because why not).
I hope this helped! Have fun with your shaders!
For the curious among us, the font of the logo and text on thumbnail is Guardian.