Jews are saved by the same means as Gentiles: by repentance from sin and faith in Jesus Christ. Actually some of John the Baptist's opponents believed that they would be saved merely by being Jews. He said:
Bear fruits in keeping with repentance. And do not begin to say to yourselves, 'We have Abraham as our father.' For I tell you, God is able from these stones to raise up children for Abraham. (Luke 3:8)
The Apostle Paul likewise taught that his fellow Jews would go to hell unless they believed in Jesus. He desired their salvation, thus indicatig that they don't have it merely by being Jews,
Brothers, my heart's desire and prayer to God for them is that they may be saved. (Romans 10:1)
Paul also told the Jews who rejected Jesus that they were responsible for their own condemnation,
When Silas and Timothy arrived from Macedonia, Paul was occupied with the word, testifying to the Jews that the Christ was Jesus. And when they opposed and reviled him, he shook out his garments and said to them, "Your blood be on your own heads! I am innocent. From now on I will go to the Gentiles." (Acts 18:5-6)
Many peopl today claim that to evangelize Jews and to preach the Gospel to them is tantamount to a holocaust. Even many churches teach that Jews have a saving relationship with God simply by being Jews. This is not true. Jews who don't believe in Jesus will go to the same hell as Gentiles who reject the Lord. Jesus is the Messiah to the Jews first, and the rest of us are grafted into the nation of Israel. Salvation through Jesus is the the promise given to the ancestors of the Jews. They cannot then reject Christ and expect for God to accept them, anymore than Gentiles can. It is of great importance to preach the Gospel to Jews so that they may be saved.