Leading friends is hard because you can’t fire them. All you’ve got is trust and example.

With no authority to fall back on, nothing happens because you said so, which removes the easy option and leaves the real ones. What you have is whether people trust your judgment and whether you are doing the work yourself. That is harder, slower and sturdier, since it never rested on a position in the first place. Friends also tell you the truth, which is uncomfortable and useful.

Do the part you are asking for before you ask for it. Make requests rather than instructions, and be specific enough to be refused. When somebody lets it slide, talk to them as a friend.