RV toilet install ?

Anyone have any photos on how they installed a RV toilet and tank?
After a couple seasons with the portable toilet I have decided to put in a Rv toilet and not sure how I am going to do it yet.
I have this area in the V that is the only place I have? but I am sure it will fit.
The vent hose is gone and all the wires are organized,my 16 gallon water tank in right there with the 12volt water pump.
The only problem I see is the space under the trailer is a odd size and I may have to make some type of tank myself to fit?
I have never looked to see how a RV sewer works?
After a couple seasons with the portable toilet I have decided to put in a Rv toilet and not sure how I am going to do it yet.
I have this area in the V that is the only place I have? but I am sure it will fit.
The vent hose is gone and all the wires are organized,my 16 gallon water tank in right there with the 12volt water pump.
The only problem I see is the space under the trailer is a odd size and I may have to make some type of tank myself to fit?
I have never looked to see how a RV sewer works?