Outside of minor adjustments to the limit screws, I don't have much experience with derailleur adjustment. After replacing the housing and cables, I'm in need of a bit of assistance with indexing after screwing up the set tension.

I've attempted to follow this video https://www.youtube.com/watch?v=92Cu_jneQFw, but I'm getting no movement from the rear derailleur.

The derailleur is currently fixed at the smallest cog with both barrel adjusters turned to provide the most slack. After adjusting the h limit screw and tightening the cable, I get no movement from the derailleur when I attempt to down shift. Anyone have an idea what the deal might be?

Cable has to be taut for the first shift to occur. Set the tension adjustment screw mid-range so you have adjustability in both directions. Then loosen the fixing screw on the cable and pull it tight, but not so you are actually pulling the derailleur toward the frame. Retighten the fixing screw on the cable. It should shift now. If not turn the barrel adjuster so the cable gets tighter. By the way, you must start with the shifter lever in the fully relaxed (zero) position. Before doing anything make sure it is all the way untensioned. Good luck.

Try this for reference: https://www.parktool.com/blog/repair-...nts-derailleur