Given the truly excellent quality of refactoring toolsets like Resharper for C# I'd wager that you're more likely to miss an edge case with your manual approach than with the tools. The tools can reliably differentiate between methods of the same name in different classes at the call sites (or between different classes with the same name in different namespaces). They will search comments and strings for occurrences of the name in question and prompt you with a nicely formatted overview dialog box which ones to adjust.

The tools are at a point where I'm usually breaking my code when I'm doing manual refactoring, but never when I let the tools do the job.