Assembling A Maru 4x4x4...

[IamWEB]

...makes my head explode.

Does anyone have any advice on keeping everything held together during assembly? I pretty much know what I have to do to assemble the cube, but the problem is I can't do it. After assembling the pieces between centers, I manage to the same between one of those centers and another one, but can't manage to connect things between 3 centers yet. Keeping previous ones held together is difficult while assembling another one. So basically... HELP!?

And is there a specific way is has to be assembled? This is because the centers aren't all exactly the same inside, and I'd like to not get anything wrong. <_<

?