i was create a backup of entirely folder before i was upgrade and test if it was working
Also just alittle tip here, for security reasons alot of software now has ways to link to that folder above the public_html. So for example i know some software that you place the templates_c folder above the public_html (to keep the public away from it) and then there is a special config command you add to the config file to point the script to access it in its new location.
However i have never tested doing this with oxwall, im sure its possible but it would be special coding as oxwal is not set up for that out of the box.
I will make a new topic for that..
Unzip to contents of smarty directory in zip (smarty-3.1.33/*) to :
ow_libraries/vendor/smarty/smarty/
if not i not sure what oxwall version you use....