Endeavor Aftermarket HU

Hey all I'm currently in the market for a new SUV and I am thinking about buying an Endeavor.  I looked at the interior last night and something that concerns me is that it seems like it would be difficult to put an aftermarket head unit in.  Anyone give me some feedback on this?  Is it easier than it looks?  Anyone done it?  Anyone offer up any resources?

Thanks in Advance!!!