Question

I recently replaced my lower unit water pump. Not before I overheated , unfortunately. While getting my repairs done, my mech told me I will soon need to replace my manifolds and risers. I want to know if this is something a reasonably mechanically inclined person can do with the aid of the Clymer's manual or if I should leave it to the pro's as I did the water pump.
How involved is the job? Any special tools needed?
BTW, the motor is a Marine Power 350 I/O with the Mercruiser Alpha 1.
And NO, MJ, I am NOT hanging a bracket off my stern yet! ;D