To use this trigger, unzip the folder and paste the file to C: / Program files (x86) / Steam / steamapps / common / Age of Mythology / trigger2
If you're like me and you're using Chrome, you might get a download block. In which case, simply go to the "details" option, then press "visit this site." If the file gets blocked, go to chrome://downloads/ and then press "keep file." I've had to do this a couple times when editing my own map.
Note: in order to conserve space, this effect doesn't include units that don't have HP. E.g. this will not increase the hack armor of an oak tree.