On Unity 4.x you do the following:
1 From the versions folder you install the PlayMaker Preview.
2 Verify that you can't edit the fsms anymore
3 REMOVE the Versions folder
4 Share project.
On Unity 5.x haven't done it myself, let me test and I'll got back to you
Typically, if you want to share an ongoing development, you should create a github or bitbucket private repository, and ignore the PlayMaker folder altogether, then you can switch the PlayMaker to preview and package this so that the person can simply install that preview once, then you can keep working as usual on both side without worrying about the preview setup everytime you have something new to share