Can someone explain about geoset merging?

Actually i'm trying to move spell breaker's head to grom's body

but its kinda hard for me.

Can someone post a tutorial or explain?

If you look down at the post "Geoset Merging" in this forum you can see that it's explained there. And if you can't find it (It is only a feeew threads down) here is the link http://www.wc3campaigns.com/forums/s...threadid=42286

that helps me alot but, still don't get the what can I say,

yeah, like Jackoo's Mitsurugi and Nightmare

becuz i just need to move spell breakers to grom

i mean, what about the grom's head? do i have to make that small?