I would first locate the existing line to make sure I have at least -1 to -2-percent slope from my rig. I would then determine the existing sewer pipe material and put in the proper "y" connection. I would trench at the needed slope and put in a threaded cap just below the surface (with box & lid). I would design that pipe run & connection (with ABS sewer pipe) so I could support the above ground pipe and also be able to disconnect(unscrew) it at the box and store away when not needed.
And if you feel the need to get a permit or have a plumber do it, that's fine too.