Add instructions for running set_paths.sh

README.md

@@ -55,6 +55,11 @@ Before installing HPVM, some paths must be set for installation to succeed. The
 * CUDA_INCLUDE_PATH --- Path to the CUDA headers
 * CUDA_LIB_PATH -- Path to CUDA libraries 
 
+Once the aforementioned variables in set_paths.sh have been specified, run the script.
+```shell
+source set_paths.sh
+```
+
 HPVM installer script can be used to download, configure and build HPVM along with LLVM and Clang. 
 ```shell
 bash install.sh