It looks like this is a common problem (see [link|https://www.headphonesty.com/2024/01/sony-wh-1000xm5-hinge-issue/|1] and [link|https://thewalkmanblog.blogspot.com/2024/09/sony-wh-1000xm5-hinge-swivel-breakage.html|2]), you can search for replacement hinges on ecommerces (AE, ebay etc...) and look at videos disassembly/repair like [link|https://www.youtube.com/watch?v=pu7Wdst1rBg|this] and [link|https://www.reddit.com/r/SonyHeadphones/comments/19cbvve/i_fixed_my_xm5_hinge_without_cutting_the_wire/|posts]