It has been several years since I took mine out. If I remember correctly, the trickiest part was popping out the pins on the on the 2 "legs" circled below. I used a plastic pry tool and got them out with no damage. Overall, If you follow the directions in the shop manual it is not a difficult job. Good luck.
Tosh, In addition to Kurt's spot on reply regarding the pins on the 2 legs check out our Help Page article on removing the dash pad at http://6364cadillac.ning.com/profiles/blogs/dashpadremoval
In terms of not damaging anything here is a key item in the help item for 1964 dashes with the sensor grill:
==> Note: If you have a 64 Cadillac with AC and the in-car sensor and plastic grill in the outer ridge of the dash just left of center be sure to not grab the plastic grill as it is brittle and will break. Also be sure not to bump it into anything when removing. Treat that piece with respect as they are eash to break!
Also.. Don't put any directly pointed pressure on the dash pad top surface especially if it is on the dry brittle site like most of them. It only takes a bit of pressure to crack thru these unless you have one that is still soft.
You said nothing about the reason you wanted to get to the fuel gauge ( a bug ? ) and remove the dash pad
That is what was vague about your question and caused the responses that you got which is std proceedure for fuel gauge problems
The times I had the dash pad off I found it a very solid piece to work with with little possibility to damage it for that reason
If you have Ac you will have a wire to disconnect that goes to the AC sensor in front of the steering wheel coming out —under the dash pad
The tricky thing I remember was getting the dash to engage the clips it goes into at the front of the
windshield when going back together