How do I produce low fat milk?

But from mystery store and then You have to use the cow upgrader. Upgrade the cow to level 3 (click on the move icon as though to move the cow but will come up with options click the house, last option, to upgrade) once cow is on right level you can add low fat gadget to the cow. I've just done this but now trying to work out how to get back to regular milk if need it lol

I have done the process of adding and removing gadgets. I'm at level 5 and task is asking for low fat milk. I cannot add that gadget. It is only letting me add l
Powder milk gadget.

I've had the low fat mission for 4 months now my cow is at level 4 on the upgrader almost to level 5 I have not seen any upgrade in the past 4 months what am I missing here I have rc but I don't even have the options to buy the parts

My cow is at level 3 but can’t find the low-fat gadget either. I’ve looked everywhere. What am I missing?

Once the cow is at level 3 hold it down and then click the magnifying glass and it will give you options of everything which you can add.

Ok so I think I finally figured out the stupid low fat milk gadget thing. The instructions posted above are wrong after step #2.
1. Get the Holstein Cow Upgrader from the Store > Animals > Upgrader
2. Level up your Upgrader to level 3 (tap and hold on the Upgrader, then tap on the building with the green arrows pointing out). Once you gave reached level 3 on the upgrader, the steps deviate from what was originally posted.
3. Instead of going to the mystery shop, click and hold the Holstein Upgrader, then click on the blue magnifying glass.
4. You should then see a window with 5 rows with various images. Row #3 has the low fat milk gadget. Click on that and that's where you will have the option to use Blue Mystron to purchase the gadget.
5. Once you have purchased the gadget, you can place it on the upgrader and then you can start producing low fat milk.

Buy the soccer workout cow in the voucher shop for 18 yellow vouchers and 5 purple vouchers.