Actually is not easy at all!!!first of all you will need a translator,since nobody speaks even basic english in the foreign police office! Their website is also not so updated so you will have to make a question visit first to be 100%. Some basic documents you need to have is ID,Passport,Criminal record,Education Degree,if you are married or have kids you will need the certifications. Check out this websites http://www.slovak-republic.org/residence/http://www.foreign.gov.sk/en/home
Articles to help you in your expat project in Slovakia