diff --git a/Readme.md b/Readme.md
index a0a4c1b3..1e2197db 100644
--- a/Readme.md
+++ b/Readme.md
@@ -19,7 +19,7 @@ The easiest way to use AFLGo is as patch testing tool in OSS-Fuzz. Here is our i
```bash
# Checkout source code
git clone https://github.com/aflgo/aflgo.git
-AFLGO=$PWD/aflgo
+export AFLGO=$PWD/aflgo
# Compile source code
pushd $AFLGO
@@ -30,20 +30,31 @@ popd
```
3) Download subject (file-utility) and set targets (commit 69928a2)
```bash
+# Clone subject repository
git clone https://github.com/file/file.git
+
+# Checkout revision 69928a2
cd file && git checkout 69928a2 && cd ..
-SUBJECT=$PWD/file
+export SUBJECT=$PWD/file
```
4) Set targets (BBtargets)
```bash
-OUT=$PWD
+# Setup directory containing all temporary files
+export OUT=$PWD
+
+# Download commit-analysis tool
wget https://raw.githubusercontent.com/jay/showlinenum/develop/showlinenum.awk
chmod +x showlinenum.awk
+
+# Generate BBtargets from commits
pushd $SUBJECT
git diff -U0 HEAD^ HEAD > $OUT/commit.diff
popd
cat $OUT/commit.diff | $OUT/showlinenum.awk show_header=0 path=1 | grep -e "\.[ch]:[0-9]*:+" -e "\.cpp:[0-9]*:+" -e "\.cc:[0-9]*:+" | cut -d+ -f1 | rev | cut -c2- | rev > $OUT/BBtargets.txt
+# Print extracted targets
+echo "Targets:"
+cat $OUT/BBtargets.txt
```
5) Instrument subject