I might not have understood correctly, though I think his question was not on the actual modification process of the hasbro helmet, but towards understanding the differences between PP2 and ESB as well as working out if the Hasbro may be a good base for a PP2 build.
As far as that is concerned...
Ive always had the impression that the eye slit of the PP2 is wider then the ESB. Th Hasbro BSs slit being wider, too, would facilitate that. I dont know, however, if my observation is correct there or if it is just an impression.
Here is a comparasion:
Upon closer inspection, however, I think the eye slit is too wide on the Hasbro.
Also the flare of the ears is too pronounced. After all... it is supposed to be an ESB
I am guessing, there are better, PP2-based helmets available in kit form for a PP2 build. That would probably be the cheaper and better way to go instead of modifiying a Hasbro. There is soooooooo much to alter with the BS helmet that its just not economically feasible.
You can see what I mean in the two threads, that
Fett 4 Real mentioned. Just take a look.