Romans road:

Understand that without God we are all hopelessly lost and imperfect with no hope for heaven due to our inability to stand before a perfect God Rom 3:23 For all have sinned, and come short of the glory of God; 

Understand that because of our moral shortcoming we are due to die with no hope of heaven but only God can give us a pardon, not earned but a gift that is received. Rom 6:23 For the wages of sin [is] death; but the gift of God [is] eternal life through Jesus Christ our Lord. 

Understand that at your worst God still loved you and sought to have a relationship with you, regardless of our efforts to be good. Your past efforts and future failure have been paid and forgiven when Christ died for them upon the cross, paying the punishment of them for us. Rom 5:8  But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. 

Understand that turning to Christ as your Lord involves turning from the sin and self will that you lived in, (this is called) repenting. Turning from one direction to another. Not that you are or ever will be perfect but that you are choosing to surrender your life to God. That you understand your eternal security is not in your own hands but secured when Christ was nailed to  the cross and gave his life for you. Understand that confession of the belief that is in your heart needs to be made, that God died for you and asked you to turn to him and will be your salvation. Rom 10:9 That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.  Rom10:10 For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. 

How do you pray for this (from the heart)“Dear God, I know that I am a sinner who deserves judgment because of my failure. I know that Christ is the Son of God, God himself that came and died, rose from the grave. I want you in my life and I turn from my old ways and my old thoughts as I give you my life. Thank you for the forgiveness that you offer and the hope of everlasting life that you secured for me. I have faith in you and welcome you as my personal savior and God, In Jesus Christ name I pray, amen.