You might be able to change the flight via online check-in (maybe not though, not sure how it works with connecting flights). If you can't do it online, you can either call the EBG hotline before the flight and see if they can move you, or request to be put on the earlier flight when you check-in at TKU.

You are in J, so this should be no problem as long as there is a free seat in J or lower on the flight you want. (I can't recall if J has restrictions).

See if online check-in lets you change anything, if not call, and worst case deal with it at TKU check-in.