Take it from someone who has been there, once you get to the wiring behind the dash panel, label the wires so you know what connects to what.
This turned out to be a win, win for me.
Now, removing the dash panel with the speedometer isn't all that difficult.
What is difficult is removing the paint on the numbers, and re-painting them where they should be painted.
Another hint, once you lower the steering column, cover it with a thick towel before sliding the dash panel out.
Doing this will prevent scratching it.
I had no reference to go by when I did mine, just my eyes to tell me what to remove, and what to leave alone.
There is a thread on another Tbird forum I belongtoo that deals with this subject.
Click the link below.
If you aren't a member of this forum, I would suggest you join it.
http://www.vintagethunderbirdclub.ne...ometer+numbers
Bob.