Its real easy acutaly. The cluster is held in by the plastic surround which has 3 7mm bolts in the top of it. Undo those bolts then "snap" the bezel out of the dash by gently pulling on it. Then there are 4 7mm bolts holding the cluster into the dash, the bolts are in each corner of the cluster. Lastly the wires unplug from the back of the cluster by fliping the black tap over (you'll understand it when you see it). Then all the bulbs backs you be exposed. The bulbs simply twist loose then you pull them out.
The small bulbs are #74 bulbs and the large ones for the tach and speedo are #198 bulbs. You can get replacements for them at any major auto parts store.