Can a SQL Snapshot be undone?

I am trying to implement a replication system in sql 2000 and in doing so have seriously messed up my database. When taking the initial snapshot of the database an new column was added called rowguid. I didn’t realize when setting the replication up that sql server was actually going to add a column to the original table. This new addition to 4 tables (and whatever else that was done) has messed the tables so that the program that needs to read them now cannot operate.

Before I go in an start deleting columns, is there anyway to undo the actions of a snapshot? Glod bless you all for any help you can give me!