Cam install with the engine in isn't bad. You remove everything but the heads/exhaust manifolds (so you can remove the lifters). Remove the lifters...

Then, open up the front and remove the cam. Tons of people have done it on the motor still installed, just go through the wheel well. I've never heard of someone pulling the engine just to install a cam.

Pulling the engine isn't much worse than that, though. All you'd need to do is detach a few cables, hoses, and manifolds then unbolt the flywheel and lift.