Greetings atthias!
You must go to the modding thread HERE:
http://www.twcenter.net/forums/showt...nd-Help-Thread
Ask there for the folder that units are in cos I cannot for the life of me remember, it's a text file, and is better formatted the the original M2TW file, you read the explanation of what each category is, find the catagory for unit size, and scroll down to the high-elves list and make that number in that category bigger!
From memory the file is something like "Export_desr_Units.txt"
OPEN IT IN WORDPAD, OPEN ANOTHER WORDPAD, COPY THE INFO INTO THE CLEAN WORD PAD, AND SAVE IT AS A BACK UP OTHERWISE YOU WILL HAVE TO RE-INSTALL THE MOD!