I will present now how update and ELM appliance .
For the begining a snapshot of the ELM machine is good to take into account, with the machine off, I advice. Another backup solution is to export all layers. Choose the one that suits you the more
I followed the citrix documentation https://docs.citrix.com/en-us/citrix-app-layering/4/upgrade.html
I got the latest sources from the citrix site https://www.citrix.com/downloads/citrix-app-layering/product-software.html
The sources are looking like that

Upgrade process
Log on onto your ELM webpage and navigate to system

select the upgrade option and browse to get the appropriate disk for performing the action




Press upgrade and wait till the page will refresh. Do not close the page till the upgrade is finished



After the refresh of the message of upgrade will be displayed

So the update is done
