To invoke SDKDiff so that you can then use menus to define the comparison, just enter
SDKDiff can be invoked with one or two paths. The second path, defaults to the current directory. If both paths are (or are defaulted to) directories then it compares the whole directories. If one path is a file then it compares that file with a file of the same name in the other directory. If both paths are files then it compares the two files. The most common cases are as follows.
To compare a file in another directory with a file of the same name in this directory enter
To compare another whole directory with the current directory enter
To compare two directories (including subdirectories) enter
SDKDiff path_to_first_directory path_to_second_directory
To compare two files
SDKDiff path_to_first_file path_to_second_file