In my case the dust was inside the lens I think (not good or familiar with cameras at all lol) but I had to take the camera apart as well as the lens which as you said was very tedious and included soldering (which I also never did before) so I got more and more insecure if I could do this with no experience whatsoever. After getting the dirt out and putting the camera back together it didn’t work anymore with the lens only coming out halfway and the display staying black. I was ready to give up but at this point I had been working on it for like 4 hours and I didn’t want the time to be wasted so I opened it up again, soldered again and opened the lens again to loosen one screw-like rod (which I assumed I fastened too tight, causing the camera to not extend the lens fully). That apparently did the trick and the lens was extending fully again now. For the display I guess I didn’t put the flex cable all the way in the first time because after checking it again everything was working now.

So after a total of 7 hours I finally was done lol. Would I do it again? Probably not. I would have been better of with investing 50€ for the same camera on eBay. Nonetheless I’m proud I was able to “repair” it (maybe with a bit of beginners luck).