diff --git a/lang_upgrade/make_source.sh b/lang_upgrade/make_source.sh
new file mode 100644
index 000000000..cf4b7fa9e
--- /dev/null
+++ b/lang_upgrade/make_source.sh
@@ -0,0 +1,75 @@
+#!/bin/sh
+# make_source.sh - step3 - replace old source files and generate new
+
+
+if [ -e ./source ]; then
+ echo 'folder ./source already exists.'
+ read
+ exit
+fi
+
+#create target folder
+echo 'creating target folder...'
+mkdir ./source
+#list all source files except *language*
+files=$(ls ../Firmware/*.c* | grep -v 'language'; ls ../Firmware/*.h | grep -v 'language' )
+#copy original source files to target folder
+echo 'copying files...'
+cp $files ./source/
+#list all source files in target folder
+files=$(ls ./source/*.c*; ls ./source/*.h )
+
+#replace source - internatinalized messages used once with _i("TEXT")
+echo 'processing msgs_en_used_once.txt'
+cat msgs_en_used_once.txt | sed "s/\\\\/\\\\\\\\/g;s/\//\\\\\\\\\//g" | while read name cols rows text; do
+ comment="$name $cols $rows"
+ if sed -i -E "s/(.*)(\b$name\b)(.*)$/\1_i\($text\)\3\/\/\/\/$comment/g" $files; then
+  echo "$name OK"
+ else
+  echo "$name NG!"
+ fi
+done | tee replace_en.out
+
+#replace source - not internatinalized messages used once with _n("TEXT")
+echo 'processing msgs_common_used_once.txt'
+cat msgs_common_used_once.txt | sed "s/\\\\/\\\\\\\\/g;s/\//\\\\\\\\\//g" | while read name cols rows text; do
+ comment="$name $cols $rows"
+ if sed -i -E "s/(.*)(\b$name\b)(.*)$/\1_n\($text\)\3\/\/\/\/$comment/g" $files; then
+  echo "$name OK"
+ else
+  echo "$name NG!"
+ fi
+done | tee replace_common.out
+
+#messages used twice or more will be listed in messages.h and messages.c.
+cp ./src/messages.h ./source/
+cp ./src/messages.c ./source/
+
+echo '//internationalized messages' | tee -a ./source/messages.h >> ./source/messages.c
+cat msgs_en_used_more.txt | sed 's/\\/\\\\/g' | while read msg cols rows text; do
+ comment="$cols $rows"
+ echo "extern const char $msg[];" >> ./source/messages.h
+ echo "const char $msg[] PROGMEM_I1 = ISTR("$text"); ////$comment" >> ./source/messages.c
+ echo "$msg"
+done
+
+echo '//not internationalized messages' | tee -a ./source/messages.h >> ./source/messages.c
+cat msgs_common_used_more.txt | sed 's/\\/\\\\/g' | while read msg cols rows text; do
+ comment="$cols $rows"
+ echo "extern const char $msg[];" >> ./source/messages.h
+ echo "const char $msg[] PROGMEM_N1 = "$text"; ////$comment" >> ./source/messages.c
+ echo "$msg"
+done
+
+
+#copy new source files
+cp ./src/language.h ./source/
+cp ./src/language.c ./source/
+cp ./src/config.h ./source/
+
+#replace line with declaration in Marlin_main.cpp
+sed -i -E "s/^(unsigned char lang_selected = 0;)/\/\/\1/" ./source/Marlin_main.cpp
+
+echo "step3 finished... press key"
+read
+exit