What the achievement asks
Research every talent in the Box of Many Things, the Torghast talent tree. Ten points, account-wide, and the pet Mord'al Eveningstar.
Seventeen entries, and a single number behind all of them: 3,510 Tower Knowledge.
Two and a half hours, not two months
In patch 9.1 this was capped weekly and took until September for anyone to finish. Now it is only a question of how fast you can run the tower.
The route people use is blunt: sprint a layer 16 wing, ignore the score, and leave. About four minutes a run, 100 to 120 Tower Knowledge each. Roughly thirty-five runs from a standing start, so around two and a half hours of sprinting.
Five-starring a run pays more Tower Knowledge, but it takes far longer than the extra is worth. Speed beats score here.
If you want the Broker's cosmetic rewards, buy them before you start sprinting. Those cost Phantasma, and sprinting past everything is exactly how you fail to collect any.
Buy these first
Two of the seventeen talents are worth having early rather than late.
The Adamant Vaults turns any Flawless run at layer 9 or above into Adamant Vaults, a whole other achievement, for free.
Blessing of the Ancients is what makes Blessings appear in a run at all, and without it Rampage can never come up.
Since you are buying all seventeen anyway, buy those two on your way through and the rest of Tower Ranger gets easier while you grind this out.
When you think you are done
Finishing this should leave you with exactly zero Tower Knowledge. If you have any left over, you have missed a box. Enduring Souls is the one people overlook, tucked away where nothing draws the eye to it.