Help!!! I was directed here and I am totally lost!!

Hi Guys, I am a professional photographer, I was directed here to get the Arduino version 1.6.5 in order to update a firmware version for my Emotimo TB3 Slider. I have NO CLUE what I am doing here... How do I go about getting this version and where can I find it on this site? Many thanks in advance !! Alan

https://www.arduino.cc/en/Main/OldSoftwareReleases#previous

Although I don't believe code that compiles in 1.6.5 will not compile in 1.8.2 so using the newest should work just fine.

There are some rare cases where code that worked with 1.6.5 doesn't work with the latest IDE versions. This sort of issue was much more common with the IDE releases immediately following 1.6.5 so it may be that the author of the instructions wrote them at that time or has never bothered to check with the latest versions to see if the incompatibility was fixed. I would prefer not to be stuck with an outdated IDE version (though 1.6.5-r5 was pretty good) but if this is a "install IDE, flash firmware, delete IDE, never use Arduino again" sort of thing then you're probably best to just follow the instructions to the letter.