You need a 10mm hex wrench. Open the top one first, then the bottom one. To refill, you need either a big syringe or a pump. The pump I'm talking about looks just like the push down pump that's used on a bottle of Vaseline - with a hose attached to it. You can either make you rown or buy one at an auto parts store for less than $3.
<span style='color:blue'><span style='font-size:14pt;line-height:100%'>Member of the Out of the Closet "I Listen to Metal and own a Bimmer" Club</span></span>