The task of hacking someone's OK Cupid account is, hopefully, a hard one. A more pertinent question for you to answer may be 'WHY would you want to hack someone's OK Cupid account?'
There are a few reasons you may want to do this, none of them very savoury. Read on and see if you can recognise yourself:
This is the most likely motive for your wanting to hack another person's dating profile. Jealousy is never attractive, never productive and never healthy.
Perhaps, by accessing someone's OK Cupid account, you hope to play tricks on them, make them look silly or ridicule them. There's only one guaranteed conclusion to these actions - you will make yourself look like a pretty nasty person.
You want to help
Or, rather, you want to interfere. Maybe your motives are a little less sinister and you want to give someone's profile a positive boost to help them meet someone. Good intentions, bad idea.