Need some Dashboard help - Remove Speedometer Assembly

I've got a '95 Rodeo 4 cylinder, 5-speed. One of my dash lights has been out and I tried to replace it last night. Screwed up in two respects. One, I twisted its grey base out and it fell behind the white plastic assembly. Two, I broke my orange speedometer arm. So, to fix both of these, I'm looking for detailed instructions on how to remove the speedometer assembly. I also need to know where I can buy a replacement speedometer arm. What boobie-traps should I watch out for? Is there anything that can come apart and be difficult to get back together? Thanks in advance for your help.