I put one in my boat Saturday...first time I had ever done one. It was a Dual Pro, 3 bank, Pro Series. No problem at all. Instructions are straightforward and easy to understand. It took me about 1 1/2 hrs to pull the old one and install the new one, and I had to end up relocating my cranking battery a few inches...if I did another one, I could do it half that time or less.
I have 2 trolling batteries and the cranking battery...the charger has one wire with 2 leads from each bank to connect to each battery...red to positive, black to negative on each battery...nothing to it. Biggest decision will be where to mount it.
Go for it...if I can do it, anybody can. If you've not already bought your charger, I highly recommend the Dual Pro...it is a heck of a product.
Good luck.
Billy