Repair mirror?

[Esteri]

I must be missing something extremely basic, but I can't figure out how to repair mirrors.

I've got a Forge follower, I talk to them about the mirror. They say they need a Bronze Spintria, of which I have several. I have NO idea where to put the Bronze Spintria - when I replace it where the Cracked Mirror is as the subject of our discussion, it doesn't do anything. And I can't figure out where else to put it - I don't want to Explore with it, and that seems like the only other option. Help?

[Maina]

Finish talking to them about the mirror. The next step after that is where you insert it.

[Esteri]

That worked perfectly, thank you! Must have taken my eyes off it long enough to miss that several times in a row...

[vindicar]

As an extra trick, you can start talking to the follower several seconds after you start dreaming on Peacock Door. That way you can slot the mirror in soon after it becomes damaged, and skip most of the initial wait time.