2005 envoy speedometer problem

My envoy's speedometer is starting to give me problems. It is either jumping around erratically or not working at all, like it is today. All the other gauges are working except the speedometer, what could be causing this, and can I fix it myself?

Common stepper motor problem in the speedo head, can be fixed but not an easy job at home.

Also see Similar Threads -
www.automotiveforums.com/vbulletin/showthread.php?p=6988824

Have you had any success in getting this addressed since your post, lamasfina?
Sarah, GM Customer Service