To begin with, we need to make a CAD model as per the dimensions of components available with you.
You can download the sample part files from here.
Once we have the assembly ready, now you can proceed for 3D printing of the parts. Take care for suitable tolerances of your 3D printing facility/vendor as many parts require good fitting. Particularly take care for printing the phone support as the lens is very small and is required to be tight fit inside the small cylindrical extrusion.
We have used Chinese version of Prusa i3 3D printer available on Aliexpress. For getting very good quality finish we have used Kapton Tape on the heating bead heated at around 70 degrees. For PLA, we have set melting temperature at around 210 degrees.
Also to improve the finish of any type of ups and down (if any) on part, you can use some plastic putty to smoothen it. We have got some from here in 20days.