How to send my husband a divorce notice

My husband and I have been married for the past 4 and a half yrs now but we have constantly been having arguments.i have tried to work this out but it's gone a bit to much reasons being,firstly he dsnt work.he has no proper job for almost 2 yrs and I have been working to pay all the bills.he treats me badly.he is very abusive verbally.he threatens to kill me also.he never wants to spend time with me.he always wants to be with his friends all day and comes late every night drinking...he sits till early hrs in the morning drinking.he used to hit me a lot before but for the past 2 yrs he hasn't hit me but abuses verbally at home and in public.he keeps roaming the whole day out with all the roadside boys and has no responsibility at all.i want to send him a divorce notice to let him no that if he continues this way I am not gonna stay with him.he is under the impression no matter what I will not leave him.hence he takes me for granted.kindly help me understand how to send him a divorce notice so that he understands the severity of this and hopefully changes.