First time I rigged my board was very daunting.
Board > Universal > foot thingy (as per your last photo)
then foot thingy > extension > mast
1. Look at your sail. Printed on it will be Luff and Boom numbers. Luff is how tall the sail should be, boom is how wide.
2. Your mast will be shorter than the required luff of your sail, thus the extension. if your mast is 430cm and the sail requires a luff of 450 then set the extension to 20cm.
There are no numbers on your extension, they look like 2cm increments, and a 5cm gap at the bottom. So, for 20cm count 8 holes.
3. Mast > Extension > foot thingy (what is it called?)
Insert all this into the sail (actually I usually just do the mast, then add the extension, i think). There is a technique, search you tube for windsurf rigging for some examples.
4. Thread the dowhaul rope (attached to your foot thingy) through the bottom of the sail and so on. Again you are going to need a diagram.
5. Downhaul. Pull the sail down the mast with the dowhaul rope, now threaded correctyl, all the way to the bottom. Yes really.
6. Attach boom to mast. we can't see you boom so can't help you there.
Same story as the Luff. Set the boom length as per the printed number on sail and pull all way to end.
7. Connect rigged sail to board. Adjust boom height so is about 3-4 fingers off end of your board (a guess there)
8. Enjoy.
(If you're brucie, I'm going to kill you)