Change from sqlite to postgresql on Ubuntu

I have a quite simple django application that uses qrlite as database (on Ubuntu). Now I want to copy all the data of this database to a new postgresql database. This postgresqldb is already created. What I have to do:

• copying everything of my sqlite to my postgresql

• configuring my django project to use the postgresql

I'm using: Postgresql 9.3 Django 1.7

I know it's a quite open question but I found so many different solutions and I don't know which one to try. I'm working on a real server so it's not the time to test different methods. Is there someone who can give me a good guide?