If you are trying to simply remove the front element, instead of reversing it, the 'vacuum' pads are not really necessary. The entire front ring that holds the glass element unscrews. The photo shows the entire front assembly removed, on the far left, but not very well.
Perhaps try putting the lens in the fridge in a sealed plastic bag for a while and then try unscrewing the front assembly again. And if that does not work, try holding the lens by the front in your hand for a bit. The front might expand slightly faster than the rest and make unscrewing possible.
Also, I'm not sure if taking the lens apart for macro shots is really worth it. If you are after shots similar to those shown in the video, you can get them with a set of M42 extension tubes with no risk of damaging your lens. (I do like the video, though.)
Last edited by sjp; 07-29-2021 at 07:19 PM.
Reason: Additional comments.