In any case and in any situation – do not leave without getting professional support.
Discreetly share your intention with a domestic violence expert and with someone close to you.
Inform your abusive partner of your wish to separate only after you have moved away to a safe place.
Make sure your abusive partner is with a person close to him when you inform him of the separation.
Refuse any meeting with your partner that is not the presence of other people, even after the separation.
Make sure a professional entity contacts the abusive partner, to accompany him through the separation process.
If there is a firearm in the house report this to the authorities as soon as you leave, in order to restrict his carrying the firearm.