Ok, just check these two, beginning with Linux-headers and Linux-image :
Linux-headers-4.9.189.......
Linux-image-4.9.189.......
And click install on the bottom (in MX Package Installer)
(Same for all, 5.2.8 etc.. )
Tip: If you first type the numbers in the search box above, it'll be easier to distinguish among others.
P.S. Next boot, you'll find the option for kernel 4.9 under advanced boot options in Grub menu to start the pc with it. But for 5.2.8 it will be directly on the list. As the system automatically uses the highest kernel found, by default.