Geocaching Australia

I am aware of a GC cache where the CO is no longer playing the game.
I want to add some information to a log in GA to keep the cache alive.
I know that there is at least one cache where you have to go to this site and search back through old logs to find the information that will take you to the cache.
I think it could work here.

Is this your log?
Is this on a GCA geocache?
Then you can edit it from the geocache page, look for the edit icon next to your log.

If this is not your log.
If this is not a GCA geocache.
Then you're out of luck as you can't edit logs that you don't own and you can edit logs that originated from a 3rd party site.