Just wanted to say that this is my first contribution, I've had a look through with the search function and found nothing. Now, most people probably know this already, but I thought I'd post it just to help some people who don't already know this.
I found this helped when using Mjollna's CataToLkM2 converter when converting multiple files. Converting the files changes the extension of the files to .m2_lk or .skin_lk and manually changing them back to .m2 or .skin files can take a while when changing 100+ files.
To make it a whole lot faster you can hold shift and right click the folder containing the .m2_lk and.skin_lk files and click open command window here and typing .ren *.m2_lk *.m2 or .ren *skin_lk *.skin
Hope some people may find this useful