The ol’ hack ‘n slash

[Oregonerd]

How to slice a box to create a lid and base

I have created a hollow box that will fit my harmonica. I have the outside sculpted and all I have to do is cut it in half to create two separate pieces. I have seen a description of cutting a pipe or the microphone but each of those deletes the other side. I don’t want to remove anything just slice it in half. Also, I am an absolute beginner so any instructions should please be written as if for a young child and step by step. I get lost in some of the videos when I can’t tell what options …