Help modifying Hori HRAP EX PLEASE

I recently bought an HRAP ex for SF4 and i bought some Sanwa buttons for it, but I dont know how to get inside of it to put them in. Is it from the bottom or the top, im new at the modding thing, if anyone can help it will be greatly appreciated.

Please, please, please post anything that has to do with the HRAP EX in this thread:

And I answered you in your other thread:

Hell, even this: