Strength foundations
A pull-up is a strange goal because it is almost purely a strength problem, which makes it one of the few things in training with a clean answer.
The block is three short sessions a week: hangs, heavy rows, band-assisted work reduced by a fixed amount every fortnight, and one negative done slowly enough to be unpleasant. It is repetitive on purpose.
I will not promise you the rep. Around two in three people get it inside the eight weeks, and everybody who does not is close enough that it arrives in the following block. Either way your back and grip come out of it transformed.