I highly recommend using the NeoLemmix version of this pack! All newer updates are just made for the NL version nowdays! Also it is way more convenient to play there as in Lemmini 
You can find it here:
http://www.lemmingsforums.net/index.php?topic=2175.01.) Download Links:Lemmings Reunion (v 1.5):
https://www.dropbox.com/s/ir0zw4qke3f4ngi/Lemmings%20Reunion%20V%201.5.zip?dl=1Lemmini:
www.lemmini.deLemmings for windows (if needed):
https://www.dropbox.com/sh/ugpmlpv4x6urg72/AAADQ3X8m--M4or_akcmeUo2a?dl=12.) Installation:Step 1 is ment for people who doesn't even have Lemmini. Step 2 is the pack installation.
1.1) Download everything and put "Lemmini" and the files for "Lemmings for windows" in different folders.
1.2) Run "Lemmini.jar" in the "Lemmini" folder and select the "Lemmings for windows" folder as the source and the "Lemmini" folder as the target
2.1) Make a safety copy of the "Lemmini files"2.2) Copy the "Lemmings Reunion" folder of the pack into the "levels" folder of "Lemmini" and overwrite the "styles" folder of Lemmini with the one from the "pack".
2.3) Copy the files in the "Packs" "music" folder into the "music" folder of "Lemmini"
2.4) Have fun
3.) Some wordsIt was back when I was ~ 4 years old as I played Lemmings for the first time on my fathers Dos pc. I loved it from the first moment on (even though I got only to the first repeats of Tricky) and began to create drawings of levels with skillsets, timelimit and everything. The level were simply "build to the exit" ones, but nevertheless I always wanted to create my own levels.
I searched and searched for an editor over the years with no success (the basic game and Oh NO were finally played through).
But then through some random Youtube search I found Pieuws, Dodochacalo's and Lacktardos custom levels for Lemmini. I downloaded Lemmini and played DoveLems which (and the single custom levels of course) opened my eyes in terms of what is possible with Lemmings.
I also stumbled across RTW's playthroughs at this time which gave me a gooood time.
PimoLems and Revenge of the Lemmings later as I was uploading the "Revenge" solutions I came across a comment from 84kingmartin which had the question in it, if I make also my own levels and I thought: Yes Icho why don't you make your own levels, you know that there is the Lemmix editor which works with Lemmini out there.
And so the creating of the pack started and now it is finally done (lil me is cheering in the backgroung

) and I hope many people will have fun and frustration

with it!
4.) RatingsI'm too young to dieNoKnight Shall Die!:

In the first rating you will encounter tutorial levels, a
few go to the exit ones, levels teaching you basic tricks and your first real puzzles. Don't expect it to go as slowly as the original game! (The final level of the rank will prob a spike as it counts on you using a bunched of tricks you learned so far)
(Fun-Tricky)
Hey, not too roughRock and Metal:

Puzzles are getting harder, the tricks you learn will be advanced ones and even some pixel-precision will be needed.
(Tricky-Taxing)
Hurt me plentyWhispers and Lights:

It gets a lot harder here. Levels getting way more difficult and longer and you have to frequently use all the tricks you learned so far. Sometimes think outside the box!
(Taxing-Mayhem)
Ultra-ViolenceA.M.:

Now it's on! It is getting frustraiting sometimes and you have to use everything you got.
(Mayhem-Beyond)
Nightmare!Justice for Heroes !:

Are you serious? Let's find out! The first ~ 15-18 levels will be just plain hard, but then

. I am no longer your friend here! I am your worst nightmare! Levels are mostly long, complex, require perfect precision and everything out of your trickbox. They will be frustraiting, but consider: THIS IS THE NIGHTMARE! RATING and not the cuddle one!
(




)
5.) Thanks to: 84kingmartin for encouraging me to create my own levels
Pieuw, Dodochacalo and Lacktardo for inspiring me (their custom levels were the first I saw and opened my eyes)
RTW for entertaining me with Lemming playthroughs all the time
namida for helping me along the way and getting me also into NeoLemmix (further all his created packs)
möbius for giving me some advise along the way and for mobilems
The whole community for letting the Lemmings live on and also for Revenge of the Lemmings
6.) CONTACT INFO:email you can reach me at: ScavengerW@gmx.de
Youtube:
https://www.youtube.com/channel/UC4Elfo3E1jTl-SHlOy97kwANow have some fun with Lemmings Reunion and send me a few replays to get these pesky backroutes!