Listen carefully when someone instructs you how to assemble the furniture.
verb To tell (someone) what they must or should do.
Usage note: "instruct" is less forceful than "order", but weightier than "advise"
verb 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.