His chest requires a magic unlock spell which is why have the glowing padlock on it if it is the one I think you mean. You can however teleport the chest away from the glowing lock and open it without a key (an unintended development glitch/bug but useful with those kind of chests) if don't have unlock spell or scroll. If you do not mean the magical one then destroying some chests will open them too. If can't destroy it, if not a magical lock one that can bypass using trick mentioned and if do not have any picklocks or skilled in their usage if is a non-magical chest then not sure what else you could do.
Last edited by Dragoonlordz; 09/07/14 07:39 AM.