To restore direct speech, undo the three shifts and put the words back inside quotation marks.

Every change made going one way is reversed going the other, and in the same order. The only genuinely new step is deciding what sentence type the original was, which the reporting verb tells you.

He said that he was busy that day. → He said, "I am busy today."

pronoun, tense and time word all restored

He said, "He was busy that day."

the quotation marks added without undoing anything

Where it bites

The reporting verb is the key to the whole reversal. 'Said' gives a statement, 'asked' a question, 'ordered' a command, 'exclaimed' an exclamation.