Change backround on a few pictures...

I need somebody to change the backround on a few pictures for me. He wants either it to look like its on the beach, with the ocean in the backround, or mountains, or something cool. If you guys could do that for me Id greatly appreciate it.

Here are some pics:














If you could do one or two, or all of them or however many that would be awsome. Thanks for the help in advance!