Easiest way to stab motor??

[Fastest32]

I'm hoping to install my 250 this weekend. Weather permitting. I had the head off the motor when I pulled it and was barely able to get it over the core support. I'm pretty sure I'm gonna have to pull the hood, but how much of a pain is it to remove that core support and grille? The other question is can I stab that motor in the transmission with the trans in place or should I back the trans up and install it after? It's a sm420 trans with the bell housing mounts.