You can only remove Shared Documents from your account if you have ‘Edit and Share’ access to the document. If you were only granted Edit, View, or Comment access, you will need to contact the document owner to remove you. 

If you don’t have ‘Edit and Share’ access to the document: 

1. Locate the document owner by going to the document and clicking More Options.

2. Click on Show Details and locate the document owner in the right-hand panel that pops up. 

3. Contact the account owner and ask to be removed as a collaborator from the document. 

If you have ‘Edit and Share’ access: 

1. Click on the Sharing Options of the shared document you’d like to remove from your account.  

2. Under Collaborators, click Manage. 

3. Find yourself in the Collaborators list and click the ‘X’ next to your name.

4. Confirm that you would like to remove yourself as a collaborator on the document.

Feel free to reply to this post with any questions you may have!