Change one layer of a DWG

I have a landscaping plan in PDF and DWG formats. Since the landscaping plan was created, the building shape has changed. The building was previously rectangular – and now it is curved. I need to replace the old building shape with the new building shape on 8 pages, and then adjust the surrounding landscaping elements so they fit properly against the new building shape. There are also two sets of stairs to replace with landscaping, a retaining wall that has changed shape, and a new swimming pool shape.