A few weeks ago Google updated Google Docs with a very useful new feature: suggested edits. With suggested edits, you know longer need to type 'delete [this]' or 'replace [this] with [that]'. Instead, simply type what you would like to happen, and it suggests the edit without affecting the document.
To make a suggestion, choose 'suggesting' in the menu under the 'share button'
Now, whatever you write, replace or delete will appear as a suggestion!