How can enlightenment be achieved according to zen buddhism?

These don't exist when learning Zen or Chan. wisdom is merit of your mind. dharma is the foremost wisdom one needs in ones life. Its also said even when you learn something it best the let it go that this merit does no good in the next life. I can explain wisdom is like the ocean its big , moves and may carry you to further gains. but these gains only carry more burden. So dharma is gain for here and now but not further. its like the last drop of water in the cup, the cup may have been full when it was filled but the last drop is what you had so no more is needed. This last drop is here and now but carries no further burdens to you. When you learn something you never forget it but use it in every part of life then when it time to release it you let go cause no gain is needed from it.