I asked this in the trailering & towing section, but haven't gotten an answer. I'm new to this type of trailer, so bear with me. I have a tandem axle '07 EZ Loader for my ZX190. I'm just wondering how to check the lube & refill on this trailer. It has the flat cap over the bearings & I'm used to the nipple type that you fill with a grease gun. Any help with how to get these caps off and check the lube will be greatly appreciated.