The tutorial worked fine for me.
The blue plastic opening tools were useless for me, as the iPod’s case seam was to thin.
Instead I used a scalpel first and then the metal spudger for leveraging and the ‘1.5" Thin Putty Knife’ to open the case.
I detached the cable by flipping the clip as described.
Attaching the cable again was no problem using the plastic spudger to turn the clip back to its ‘close position’.