Sorry if this has been asked multiple times but I have no idea how to do this and I did a quick google search that didn't help me.

I've downloaded fm8 from the site and it says to 'give specific permissions' to it after installing and replacing the files.

I have no idea how to do this. Someone once showed me something with batchmod, I'm guessing it's using that but I've completely forgotten what to do.

If anyone could provide any assistance I'd be very grateful.

 

If the app not running and jumping on the dock use this method working for me in most of the cases.
(I don't know if it's working for you or for FM8 I never have FM8)
But in general use you can try this way.
1. Open BatChmod, then File, Application, FM8 (or any app that needs permission reset), click to open in BatChmod
2. There will be empty w boxes, tick on them then apply.
If didn't work
3. This time tick the Clear xattrs box then apply
in most of the time it will work.
In case those didn't work you can try Permission Reset download from here
http://www.macupdate.com/app/mac/31741/permissions-reset
Goodluck

 

Thank you very much.