If you want to change locations within your province or metropolitan city, you should speak with your MOE/POE supervisor. They can give you more information. If you want to change locations entirely (going from Ulsan to Seoul for example), you will need to reapply directly to EPIK.
If you want to change locations and program, then please fill out Korvia Alumni re-application form. Korvia Recruiter will assist you to find the best chance to relocate you.