It’s a bane for photographers: There is always a little detail in the picture that we would like to remove. If it is an ugly little spot your best graphics suite will do. If it is something much more annoying (a fence, people, etc.), it may be a near to impossible task.
Now, if you are willing to reproduce the exploit of some geniuses of graphics editing but do not have the talent, you may use a tool for Windows: PhotoWipe. You only have to brush over the parts you want to remove and the software program will remove it automagically.
You cannot expect it to work on all subjects, but removing a wire, a fence or over complex patterns in front of a relatively predictable plain subject is feasible. The utility will compute the most probable background from surrounding hints. It does not always work, but it’s worht trying to salvage a picture.