A vise with rubber pads will be fine.
You don´t need Lego - just something that fits, like wood or paper,....

The tool I use is just a round piece of stell which is flat at the end. It should be bigger than the hole for the 510 in the base.
If you don´t have that then try a thick nail which is flat at the end and hit around the 510 inside the base in a circle to loosen it.

Under the AFC you´ll find the two parts which are shown in the first picture of this thread. There is also a little spring for the little metal ball.
So tape the AFC - it helps that it doesn´t move when you disassemble the base. So you don´t lose those small parts.

If you are lucky the LC will just work the way it should. If not you should open the base.
In step 3 you can see that the O-Ring is damaged. So I changed it and put a lot of VG on it.
Can´t remember if that one came with the Ammit or not. I have sooo many O-Rings....

Same trouble with the Merlin because of press-fitted base - also connectivity problems.

Maybe best if you vape a bit with the Ammit before doing all that....

P.S.: You find my mail-address in the thread with the dry hits!