I have low cylinder pressure (100PSI) and an slight misfire on #3 and was thinking about pulling the head (drivers side). Is it as hard to get in there as it looks? How long should it take just to do the one side?

 

I assume you mean a 3.9L?
It's not as bad as it looks, but plan on taking a whole day to R&R the head.

 

I agree, it's not as bad as it first appears. If you do it once you'll be an expert for the next time.
I pulled my front seat out of the way so I could sit down while doing it. I do my best work sitting!

 

I just did this on a 5.9 and it took me 6hrs to get the head off. Got a re-man'd head and about the same to put it all back together with an oil change and tune up. I was reading 0 in one cylinder and had great values everywhere else. Turned out to be a bent exhaust valve. One I put the new head in I was reading 155 across the whole pass. side bank.

I chose not to do the other side as I had no issues over there but there is the question as to what happens if it goes south. My answer to that is I do it again in even less time now knowing what i have to do.

Just go slow, label all wires, and keep your push rods and rocker assemblies in the order they came out.