Listen carefully when someone instructs you how to assemble the furniture.
1751, Samuel Johnson, The Rambler, No. 156, 14 September, 1751, in Volume 5, London: J. Payne and J. Bouquet, 1752, p. 177,
[…] the design of tragedy is to instruct by moving the passions,
(transitive) To tell (someone) what they must or should do.
Usage note: "instruct" is less forceful than "order", but weightier than "advise"
The doctor instructed me to keep my arm immobilised and begin physiotherapy.
(transitive) To give (one's own lawyer) legal instructions as to how they should act in relation to a particular issue; thereby formally appointing them as one's own legal representative in relation to it.
If you're not careful, I'm going to instruct a solicitor over this.