I cant get the wiper blade arms off my '66, I see a little piece that looks like you have to push in for it to come off, well it wont come off, any advice?
You have to pull it straight up as there are little grooves within the wiper arm and the "stub", that connects to the wiper motor. Once you lift it up about 1/8", you'll notice that the little tab you are describing will need to be pulled out of thr way to clear the stub. Move it to the side and continue to slide the arm STRAIGHT up. It's hard to do because I'm sure you don't want to chip your paint. It probably hasnt been removed since it left the factory so its on there real good.
pry it off with a screwdriver. Wedge it between the end of the wiper arm(by the pivot) and the sheetmetal on the cowl. Wrap the end of the screwdriver with masking tape or similar material to prevent scratching.
I have a really good, simple wiper arm removal tool that came from K-D or Lisle. Check at a parts store that has a good selection of these specialty tools. It basically hooks under the end of the arm, then you raise the arm up against the spring that holds the blade against the windshield. Once the spring load is released, you just pull the arm off the shaft. The little tab you see at the base of the arm doesn't affect this.
Here's a tool similar to the one I have that I found in the Snap-On catalog: