I suggest you go to a store that sells watches and let them do it. They usually don't charge that much for it, if at all. Also, they have all the necessary tools, so hopefully, it won't get damaged.

I've never changed the battery on mine, but I've pulled out the thing on the side (can't find the right word for it atm) so that it doesn't run.

Hi Griffle

I've just had a look at my Pocketwatch & can't see anything at the side which you say is on yours which you have pulled out. Do you mean the part what the chain is attached to? The watch didn't come with any instructions so am just confused as don't even know how to change the time let alone the battery. I will prob have to take it to a watch place am just scared as don't want any scratches they might accedentialt do.

Yes, sorry, at the top (of course! Was thinking of a normal wrist watch).

As it turns out I hadn't pulled it out anyway, so the battery is dead.

I can't seem to find a way to open it either. Sorry I can't be of more help.