How to update the game through Steam? {Simple} Please Help!!

So I completely deleted my game and then downloaded it through Steam using the Code. That was about a month ago. But I opened the game today and started to re-install all my mods so I could play again, but I'm having some issues. Whenever I load any map, this immediately happens.

I can't do anything except quit and if I don't the game eventually crashes - however I think I know the problem. I was installing a map that also edits the lua files and I messed some stuff up with merging and replacing. So my lua file is super messed up. I could simply update the game and then load up all my mods again, excluding this one, but I have no idea how to update my game since it's all through Steam now. This is probably a really stupid question but how do I get a fresh game now? Is it the same method as before or do I have to do something in Steam itself?

 

This is a question I would like to see answered as well. Being able to download a clean game after thoroughly destroying another was really handy. Luckily I haven't had to do that after Steam but I intend on seeing
if copying the standalone game files to a non-Steam folder will work.

 

Just delete all the files you think are corrupt and use this. My cursor didn't show up on the SS but I'm referring to 'verify integrity of game cache'

 

I'm busy right now but I'll try that soon. Get back to you later if it works or not. But thanks!!

UPDATE- I deleted the lua file as well as the corrupt map and did what you said. Everything works! Thank you so much. I'll keep this in mind for the future!