One wrench, a bit of disassembly (take photos along the way), easy part swaps, and reassembly and now I’ve got a washer that actually agitates again. Time will tell how it handles heavy loads; it originally failed while washing a painter’s tarp.
Note: I didn’t end up using the black cone piece, as it didn’t fit my model, but everything else in the kit fit perfectly and went in without a hitch.