Editing multiple walls due to downsizing square footage of print

[Hurtmd5]

Software type X12.  This is my first time using this software so I am learning everything as I go.  I have a print that I had the preliminary done on.  The customer has decided to remove 6' from the middle of the house to reduce the square footage as they want to reduce the living room/kitchen, but will also have to adjust the garage and front/back porch.  Is there a easy way besides for having to do every wall individually and then also adjusting everything on the left side of the house?