This guide will show you how you can clear server cache.
Find your FiveM game directory. (this would be on your users appdata > Local by standard!)
It should look like this:
Open up FiveM Application Data. This should look like this:
Open up the "cache" folder. it should contain the following folders and files:
If you don't have these folders, you have to start your client and join a random server, but that would be pointless because your cache would be clear to begin with.
Now that we are in the cache folder, you need to delete everything EXCEPT for the "game" folder!!
Now you can start up your client and start playing. Do note that clearing your cache WILL get rid of your favorites, recently joined etc. You will have to redownload custom files that servers stream for ex. cars, peds, weapons etc.
Thats how to clear your cache!