Let's just put alcohol aside for now, and try to cut down on your smoking a little.
You should try to cut back on the number of cigarettes you smoke first, and then deal with the alcohol later.
ーLet's just put alcohol aside for now, and try to cut down on your smoking a little.
「お酒はともかく、タバコの量を少し減らしなよ」
to put alcohol aside で「お酒はともかく」
to cut down on ... で「(タバコなどの）量を減らす」
ーYou should try to cut back on the number of cigarettes you smoke first, and then deal with the alcohol later.
「まずはタバコの量を減らしたほうがいいよ。それからお酒の方を対処したらいいよ」
to cut back on で「量を減らす」
to deal with で「（問題に）対処する・取り組む」
ご参考まで！
カナダ 
