How to encrypt and decrypt pre populated sqlite database step by step in ios using sqlcipher?

i made an application that my data source is sqlite.db .i made this database by Valentina Studio application.now my database is added to my target and it's not secure.i add sqlcipher to my project like this tutorial http://ift.tt/1BqPoOi. but this sample code just made a encrypted new database.anyone can help me to do it step by step?