If you make this manually you can use wordpress default "import" tool which you navigate from wp-admin/import.php .
If you make this automatically you can use Atom or RSS feed.
If I were you I would install https://wordpress.org/plugins/wp-rss-aggregator/ this plugin and pull all post via blogger RSS
- Atom 1.0: http://blogname.blogspot.com/feeds/posts/default
- RSS 2.0: http://blogname.blogspot.com/feeds/posts/default?alt=rss