BMW 323i 2006 rear strut problems

As a noob, doing suspension work is not where I would start. But you would need to have a level working space, jack stands and a jack. Maybe a friend can help? From the photo, the shock pushed through the shock mount. I would purchase a shock mounting kit from fcpeuro. That would include the mounts and new bushings. $110. Then purchase two new shocks, about $120. You will need a breaker bar, a good sockets set and wrench, rags , eye protect, etc. You will also need to remove the inner panels in the trunk. Check out some youtube videos. Search BMW E90 shock DIY to get an idea on what you will need to do. I would also have the wheel checked out, it might be dented or cracked.