Thought I'd share the story of how I weened Charlie off the mirror I made the mistake of giving him 6 or 7 years ago.
He had a smaller mirror by his feed bowl that he never seemed to interact with in an unhealthy way (he played with the bell on it more than anything) and I wasn't familiar with the idea they were bad for them at that point, so I got him a larger mirror to hang by the bars in the upper part of his cage (he has French moult disease and couldn't fly so I got him an extra tall cage so he would get a lot of exercise). He would often put his foot on the bars and press the mirror against it to chat.
With this second mirror, he almost *immediately* got obsessed with it, feeding it constantly (it got to the point where I was having to clean it virtually every hour or two) and if I removed it he would shout and shout and shout and shout endlessly. Obviously I knew I'd made a mistake and now had a problem in that I didn't see how I could take it away from him... I fact, on the times I DID remove it for long periods he would simply go over the spot where it would usually be, put his foot on the bars like he would when it was there and regurgitate onto the bars instead!
So I had to find a way to have it in the cage and stop him from being obsessed, whilst also not having it in the cage. Then I had an idea... Whenever I took it off to clean it, he would always get excited when he heard the chain jangling as I returned it before he actually saw it, so one day I replaced the mirror with a rectangle of cardboard, shook the chain so he got excited and then put it in. He sort of stood there looking at it as if it to say ".... huh?!" but then cheerfully returned to talking and feeding it like it was his mirror.
The immediate issue solved was that I could just replace the cardboard with a new one rather than having to clean it, but I could also gradually change the size of the card without him noticing so I eventually got it down to a small square and then moved it away from the bars so that it dangles in the middle above his perch, where he has to reach up to interact with it.
He stopped feeding it at this point and I started cutting the card into various different pretty shapes (being careful to avoid sharp edges etc) which he now just likes to sit under and occasionally chat to in that sweet way they do and doesn't care if I take it out for long periods.
So yeah, that's how I managed to ween Charlie off his obsession with mirrors when I made the mistake of giving him some.