How could Satan tempt Jesus?

Temptation comes from the heart. Jesus did not want to die and he did not want to be made to be sin. This is why he prayed, 'Take this cup...'

But he submitted his will to that of the Father.

The same temptation hit him continually through his ministry.

To Peter: 'Get thee behind me Satan' because Peter suggested that he need not die.

Jesus could be tempted to not die because there was no sin in not facing the cross. His was a free will offering.