Memoirs have the power to be as compelling as works of fiction. But this doesn't mean you invent things that didn't happen! Writing a memoir 'as if it were a novel' simply means that we enrich the writing by employing many of the same techniques: luscious description, compelling dialogue, multidimensional characters, etc.
So rather than sitting down and telling the reader 'what happened,' can you invite the reader into your experience and paint the scene AS IF you were writing a novel?
The reader needs to be able to conjure in their imagination the people and scenes that you can envision in your memory. So can you write about the people in your memoir as if they were characters in a novel? How does the scene sound or smell or feel?
How can you pull your reader into the story so they feel they are stepping into an imagined world?