The script that you are referring to is a Bash shell script and not a Python script. Therefore you need to make sure to run it in a Bash shell. How to do this has been discussed on SO before (see here). You could install Cygwin or MSYS, and it would probably work. However, if you just need to run this simple script (and not too often), this would be rather overkill in my opinion.
Alternatively, you might simply want to run the commands from the script manually in SQLite using SQL (e.g. with sqlite3 command line tool or probably even a GUI interface such as DB Browser for SQLite might work). All the SQL commands are written at the bottom in the script, lines 31 to 36:
ATTACH DATABASE '$1' AS source;
REPLACE INTO map SELECT * FROM source.map;
REPLACE INTO images SELECT * FROM source.images;
You need to do this with your destination database open, and
$1 is the path to your source database. Not very elegant, but should work.