Edit .pbo trees or grass?

Hello Guys,
is it possible to edit this tree or grass datas in ArmA2?
Since the last update in Dayz Epoch you can remove Grass and trees without getting kicked.
I want to edit tree shadows that i cant see the whole trees.

edit:
I opened the trees.pbo file and now i have a lot of .p3d and .paa files.
I tried to open this files with TextView2 but i cant. I get an error message.
Need help

Try to open it with Hex Workshop it works for me

This method should work if you locate the tree files instead of the grass files http://www.mpgh.net/forum/624-dayz-m...utorial-d.html