Looks like I have a blackout concerning the instrumental case

"Мы проводим Новый год водкой" ..
Наряжаем ёлку всей семёй...
Я пишу ручкой...

The third one is very obvious...it is kinda tool I'm using in order to write

But 1 and 2 is not very obvious in my opinion. In this case, Vodka must BE ESSENTIAL in order to leave the year behind???


If I write C ...it would like spending new year with the bottle of Vodka in my hand or what??

need detailed explanations...

thanks in advance