Wyse OS install to different drive

Hi, we have around 70 thin clients running windows ltsb, windows updates are now not really happening due to a lack of disk space. we bought a few m2 ssd's to test with. i've installed it and it's recognising it fine but how do i get the OS to install on it?

i downloaded the wyse imaging tool and ltsc 2019. it installed ok but onto the existing 32gb emmc and not the new 240gb ssd. there was no option to either?

is this possible, can anyone help?