How do you make a word in Latin a Dative case?

Question

I would like to know the step by step way.

Answer 1

1. Look up the noun in a dictionary, which will list the nominative and genitive forms.
2. Compare these to a table of declensions (possibly contained in your dictionary) to identify which of the five declensions your noun belongs to.
3. From the same table, read the relevant dative ending (paying attention to whether you want the singular or plural) and apply that.

The way you've phrased your question suggests you are completely new to Latin, and I would encourage you to learn in a more systematic way than just learning individual processes like this. The dative (and any other case) is used differently in every language and isn't very helpful in isolation.