en_tn/rom/03/25.md

in his blood

This is a metonym for the death of Jesus as a sacrifice for sins. AT: "in his death as a sacrifice for sins" (See: rc://en/ta/man/translate/figs-metonymy)

disregard

Possible meanings are 1) ignoring or 2) forgiving.

This all happened for the demonstration of his righteousness at this present time

"He did this to show how God makes people right with himself"

This was so he could prove himself just, and to show that he justifies anyone because of faith in Jesus

"By this he shows that he is both just and the one who declares everyone righteous who has faith in Jesus"