Killing people isn't easy. It goes against basic human nature which is why war is so ugly. However, when the invader comes to destroy you, killing them is necessary and required.
All of the civilians in Ukraine who have already been killed by Russian bombs and bullets have family and friends who mourn their loss and are angry at Russia. These are the people you want to recruit first. They are thirsty for vengeance and will have no problem killing a Russian soldier if given the chance.
Let them do it for you if you are too timid to do it yourself. Civilian warriors need to get involved when enemy soldiers are on your streets.
Kill the invaders. Spare no one.