Each of these translates into Spanish, or any other language, in multiple ways, so it is impossible to list them all.
The most common translations of "would" and "would have", however, are
through the Spanish conditional and past conditional tenses.
He would do it Lo haría.
He would have done it.
Lo habría hecho.
"may" and "might" are often translated with forms of "poder" ("puede ser que") or "es possible que".
There are no one-to-one (word-for-word) translations.
CJ