Planting sprouted garlic

I bought garlic sets from garden centre but didnt get a chance to plant out in autumn as planned. They have now sprouted but from what i have read it seems they can still be planted? When planting do you cover the green tips or just the clove? Possibly a silly question but I am quite new to this! I live in scotland and was going to wait til ground was not frozen before planting but could i start them off in modules in unheated greenhouse instead. Any guidance and suggestions gratefully received!