Here's the tutorial, its a very easy mod requiring very minor surgical procedures.
The Head before the mod
Pretty long & a little too lean
Next step, cut the head open as shown
The head is hollow, now all u gotta do is stuff it with stuffs like what BBQ said, putt clay or if yr real lazy even paper will get the job done.I use bubble wrap to fill it up.
Additional Note: I don't really think it's necessary to cut open the whole bottom of the head, you could probably just cut one side and make the opening big enough for you to stuff in the stuffs.
After all that stuffing, just glue the head back. Personally, I only used sticky tack aka blu-tack to secure it. Just in case I wanna do any further mods to the head in future.
After the mod, the head is rounder & closer to how bale looks in the movie.
Hope this will help everyone!
Special Thanks goes to BBQ of Toy-world.com.hk who told us how to do the modification.
Also thank you to Battyman of Toy-world.com.hk for explaining the mod to me in english.