Freeing money in blocked account (rental guarantee)

The bank will have a standard form. Call them up and ask for it, or it may be available on their website or in PC banking. It would usually be completed by you and the landlord after you have recieved your leaving inventory, which would state if there is anything to be deducted.

The above answer is correct. ING has a form which needs to be completed by both owner & tenants, with copies of ID cards, usually in front of an ING clerck to testify that the signature are originals.

Go the the branch with the landlord and do it there....