The difference between any Protestant and the Catholic religion is the belief that salvation comes through faith alone (sola fida). One's belief in the atoning death of Jesus on the cross is sufficient for salvation. The Lutheran religion teaches that Jesus is the only begotten son of God, is one with God and is a part of the Trinity of the Father, the Son and Holy Spirit. We believe that Jesus is God and came to earth in human form to save us through His death.
Good works are expected by a true Christian, but those works come through belief and are the working of the Holy Spirit within us. Nothing can make our sins any more or any less (i.e. confession, Hail Marys, etc). God accepts us as the sinners we are and has forgiven us through Jesus.
The best way to convert is to find a Lutheran church near you and attend a couple of services. Decide if you like the pastor, the people, etc. If it's where you want to go, talk to the pastor and see if they offer new member classes. In those classes, usually the doctrine of the Lutheran religion is explained. Then tell the pastor you want to transfer from your church. He can tell you what else may be necessary.
Every Protestant denomination will vary in doctrine and ritual, but the underlying belief in Jesus' death on the cross for our salvation is the common thread through all of them.
Catholics believe that during the consecration prayers the bread and wine become the actual body and blood of Christ Jesus, fully present under both forms. It is not symbolic and when it is received by the communicant it exists as the body and blood of Christ. It remains so if not consumed and is kept in the tabernacle. Simple explanation.
The Lutherans see communion as symbolic in most aspects, although they believe that the bread and wine become the body and blood of Christ WHEN it is consumed and not before. Further, the hosts that are not eaten are considered to be merely bread and the wine just wine. It is a combination of the prayers and YOUR belief that make the change.