How to reformat naming styles with ReSharper?

I don't believe ReSharper has a way to do a bulk rename like you want. Changing the C# Naming Styles will certainly highlight (as warnings) those local variables that need changing, but Code Cleanup won't correct them for you.

There are times when renaming a variable to match a convention might result in one symbol colliding with another symbol that already exists; I imagine that's why ReSharper doesn't allow the bulk rename.

Two ReSharper shortcuts may make this pretty quick (and this is assuming you have adopted ReSharper's shortcut keys for Visual Studio):

  1. Alt + PgDn - Go to next highlight (error, warning or suggestion). This will let you get from one misnamed variable to the next quite quickly.
  2. Alt + Enter - Open the "Quick Fix" menu and select "Rename...". This will rename the variable and update all references.

Starting from R# 8, there's the option to fix an issue in scope.

  1. Go to any occurrence of this issue
  2. Put the cursor on it
  3. Show potential fixes (CTRL+.)
  4. Select the first option 'Rename to xxx' and select 'fix naming in solution'

More info