update README (SimVascular#416)

Co-authored-by: Aaron Brown <[email protected]>

Author: menon-karthik

README.md

@@ -158,9 +158,10 @@ These commands will create the following directories under /user/shared/vtk/inst
 bin/ include/ lib/ share/
 ```
 
-You can then build svFISplus with the local VTK libraries using the two CMake command-line arguments that sets the option to use a local VTK build and the location of the build
+You can then build svMultiPhysics with the local VTK libraries using the `ccmake` interface to set the `SV_LOCAL_VTK_PATH` variable to the location of the local VTK build 
+or do this using the CMake command-line argument:
 ```
--DSV_USE_LOCAL_VTK=ON  -DSV_VTK_LOCAL_PATH=/user/shared/vtk/install 
+-DSV_LOCAL_VTK_PATH=/user/shared/vtk/install 
 ```
 
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