Need encouragement head replacement

[ssrcobra]

I did a restore on a 1935 4 door a few years back. When I acquired the car it had on it cast iron head not aluminum.
Not knowing any better when I had the engine done I left the iron heads on. I have now acquired new cast aluminum heads and want to change them out with the iron heads but keep procrastinating.
Will I have trouble just swapping them out or are there some tricky thing that I need to know to do this job? Is there a certain way the heads have to be torque. Should I hire someone to do it?
Any thoughts would be appreciated