If you don't want to do it by hand, you can use the old classic 2010 method as detailed in the post here(Jack's 3rd post):
viewtopic.php?f=20&t=35AttachmentAdder can be found here(use the mediafire link):
viewtopic.php?f=59&t=836Pretty simple, drag and drop your m2 file into it, enter 5 for when it asks you how many to use. , then when it asks you what type, do 0 for the first one, 1 for the second, 2 for the 3rd, and so on. When it asks you what bone, just use 0. and when it asks for X,Y,Z coordinates, do as Jack says, make a little object for you to move around to where you want your points to be at and enter them as you go.
May take a few attempts before you get a good idea on how it works but overall it should work fine. goodluck. Make sure you back up your m2 file before doing this on it.
Example: