Potentially, 2 heads means disconnecting 4 hoses.
I have 2 hoses I'll have to pull.
The aft head hose is the Trident 101 which slips on and off RELATIVELY easily. But I am putting Sealand odorsafe on the forward discharge line. That hose is much more difficult and the seacock is in a very difficult spot to reach. The hose cost me over $100. The other end is at the syphon loop behind cabinetry, also difficult to reach.