Once the fuselage is done you can start working on the float. The float is made of 4 pieces. Two for the front half, and two for the rear half. Each half consists of a top and bottom piece. I recommend starting with the top piece for each half, These pieces have a bulkhead that allows for structural stability.
When building these, start where the bulkhead attaches to the sides of the float. This will put the paper into the general shape you need to finish up the curved areas toward the tip of the float.
Once the main piece is done, you can start placing the bottom skin onto the float. Again, start at the bulkhead and work toward the tip of the float. On the front part of the float (more curved part) be sure to place the part carefully. There should not be any gaps where the joints come together. It needs to be flush at each one to ensure a proper fit.
Once the float halves are done, join them together in the center, gluing the bulkheads to each other using the printed diagram on the parts.
Now comes the fun part (sarcasm is spilling over here). The center piece that connects the fuselage and the float together can be a down right pain to get on straight. One of the first steps to success is making sure you cut the bottom half of the insignia on the fuselage free. It should stick straight down away from the rolled tube. This is where you dry-fit like CRAZY!
Once you're sure everything is set up properly, start with one of the sides and line it up at the front by slipping it under the insignia. Be sure to put some glue on the back side of the insignia and on the 3 glue tabs on the center piece. Then, start slowly lining up the part and apply little spots of glue along the piece. You will have to hold the rear point for a couple of minutes to hold it in place.
After that side is set, do the other! It should look like this when glued on completely. (fuselage is just sitting on top of the float, it's not glued yet.
Once the glue is set, add the front fairing (front piece above the float in the last picture) to the center part and it's ready to join to the float.