Hi, My grandma has an old (1990's) Loewe TV, the batteries have just died in the remote and I cannot for the life of me work out how to open it up and replace them. Can you help me out please? I can't unscrew or open the back at all, its seems totally fixed. The bottom of the remote slides down to reveal more buttons but doesn't slide all the way down. There's probably a stupidly simple answer but I just can't work it out! Thank you very much, kind regards, Lelda