A question about Hebrews

How can believers crucify the Son all over again with no sacrifice for sins left if the body of Jesus is the final sacrifice and had paid the sin penalty once for all..

Heb 6:6 NIV and who have fallen away, to be brought back to repentance. To their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.

Heb 10:10-12 NIV And by that will, we have been made holy through the sacrifice of the body of Jesus Christ once for all. 11 Day after day every priest stands and performs his religious duties; again and again he offers the same sacrifices, which can never take away sins. 12 But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God.

Heb 10:26 NIV If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left,

As I understand, Epistle to the Hebrews was written to Jewish Christians...

see the parallel of rejecting Moses' law with, how much more so, insulting the Spirit of grace..

Hebrews 10:26-29New King James Version (NKJV)
The Just Live by Faith
26 For if we sin willfully after we have received the knowledge of the truth, there no longer remains a sacrifice for sins, 27 but a certain fearful expectation of judgment, and fiery indignation which will devour the adversaries. 28 Anyone who has rejected Moses’ law dies without mercy on the testimony of two or three witnesses. 29 Of how much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace?
Jewish Christians who weren't born again?

No. To Jews who had at one time confessed Christ but who wanted to go back to the rituals of the Jewish faith.

These were still going to the temple and trying to keep the law and some were actually making sacrifices. To do so meant that the work of Christ meant nothing to them at all.

The writer of Hebrews then is telling them that they can not continue in temple worship of the Jewish faith anymore because there is no longer a sacrifice for sin outside of the one made by the Lord Jesus. So then, if a person rejects the truth of Christ's death for sin, "there is no other sacrifice for sin available to them," and that means there is no way other way to come to God.

To continue to practice temple worship would be rebellion done willfully.
The law sacrifices every year because the blood would only cover their sins. Jesus' blood removed the stain of sin. But the constant sin-repent-sin-repent cycle of the law never changed anyone. Jesus did. He broke the cycle and through Him we are free...We just have to believe AND obey.