[2005] Reading parts of a file in binary and overwriting only parts

[|2eM!x]

Ive been using FileStream,BinaryReader, and BinaryWriter for my latest project. All was working great, I was reading RinaryReader.ReadChars() and writing using BinaryWriter.Write(). However my problem arises because I thought .write would overwrite, instead it just inserts/appends. Is there something I could use to overwrite instead of append? Thanks