I was formerly able to select lines on a PDF created from an AUTOCAD file and change the properties.

With a previous version of Acrobat, I was formerly able to select lines on a PDF created from an AUTOCAD file and change the properties.  With Acrobat XI, the tool for selecting graphics has disappeared.

Does anyone know of a way to select and change the color of a line created in AutoCAD while leaving other lines their already-assigned colors?