I think the hiscore plugin was introduced in 182? In which case all you need to do is:
1) Backup your /mame/hi directory!
2) Rename your mame executable to something like mame.186
3) Rename your mame.ini to mame.ini.186
4) Install latest mame (it looks like you have an LCD monitor? In which case I'd recommend just going with the base mame and not groovymame)
5) Install the latest hiscore.dat
6) Generate a new config (mame -cc)
7) Compare the new config to the old config, make sure you have the plugins enabled (especially hiscore)
Start a game you know you had a hi score on and you should see it
Just make sure you don't have save states enabled because they aren't compatible between mame versions, they may or may not conflict with hiscores, I've never risked it because I like my high scores!
Also, one thing I have is a script that waits until my cabinet has been on for a few minutes, then it backs up all my hiscore and config files and transfers them to my NAS. So I always have backups from the last 10 times I launched the cabinet, just in case.