To delete a memory, simply erase whatever description you have given the memory, and then hit the 'submit' button.
I'd suggest to add the sentence:
This will only delete the memory, not the actual entry associated with it.
While you're at it, perhaps you should brush this FAQ up a little. For example, remove redundant parentheses around URLs, spaces around colons, etc.
I'd also suggest to remove the words "Don't worry".