Finding an easy way to migrate a sourcesafe-controlled code repository over to subversion probably isn't made any easier by starting with a complete get of the code archive burned onto a CD and no further access to the sourcesafe archive thereafter, but here's a great little post from Brian Carroll on how to eradicate VSS from your solutions and projects.

  1. Go to the folder containing the solution files and delete the following files: mssccprj.scc, MyProject.vssscc, vssver.scc
  2. Open MyProject.sln in your favorite text editor and remove the following section:
    GlobalSection(SourceCodeControl) = preSolution
   ...
EndGlobalSection
  3. Go to the folder containing the project files and delete the following files: MyProject.vbproj.vspscc, mssccprj.scc, vssver.scc
  4. Open MyProject.csproj in your text editor and remove the following lines:
    SccProjectName = "SAK"
SccLocalPath = "SAK"
SccAuxPath = "SAK"
SccProvider = "SAK"
    or 
    SccProjectName = '"$/blah/blah", RPFAAAAA'
SccLocalPath = ".."
SccProvider = "MSSCCI:Microsoft Visual SourceSafe"
You can also unbind a project from a Source Control within Visual Studio but this tends not to work on web projects in which case steps 2 to 4 work just fine.