Though we love collaborations, we know that there might be times when it just doesn't work out.
In order to remove a collaborator from your project, click the Invite icon from your profile page (1) and then click the "X" button beside the collaborators you wish to remove (2).
There are also a couple of things you could do before you start a collaboration in order to feel more safe about your project.
Make a copy of your project by going into the File menu in the studio and choosing "Save as..."
If you are a Premium user, you can use Time Restore to open up a previous version of your project and create a backup even after you've started a collab.
If you change the name in the studio, the next time you save it, you will be asked if you want to "Save as new".
(1) Profile page - Invite icon
(2) Profile page - "X" button beside the collaborator
(3) Remove User dialog box