Leo loves to be in the spotlight and to be the master of some rare and beautiful things (where he classifies his spouses as well), that are calling for general admiration.
Therefore, for Leo to leave his partner, one needs to stop admiring this King of beasts (which, however, is fraught with trouble), or start compromising him with his plain and common looks.
Refuse to go out with him, do not agree to visit any fancy parties, hang around the house in a baggy coat, at the most inconvenient time start talking about children's illnesses, demonstrate your stupidity and misbehave in a company where Leo wanted to "show off". This will be enough for him to try (of course, gracefully) to get rid of you.
Do not worry about his fate - Leo immediately will surround himself (or herself) with the huge army of fans, who dream to share with him the crown. The only advice - when you return back to your fashionable gloss, try not to catch the eye of your former spouse. Leos often live by the principle "we do not care for what we have, until we lost it".
So that, seeing you in all your glory, he might desire to have you back. Do you really want it?