Soldering in a ditch can be a bitch. I would suggest brazing it rather than soldering if you plan on DIY. Brazing it works better because your pipe and fitting can have imperfection in roundness and the braze will fill that it. However, it requires a HOT torch and oxygen in the ditch and NO water in that pipe to boil and cool your work.
If you plan to use solder, definitely get a rounding tool to fix the pipe. Any gaps will cause it to fail. In a repair situation, solder from the bottom to the top because that is where you're likely to have water and if you can't solder the bottom, theres no reason to solder the top of the fitting.
Not sure if you're having issues with water in the line, but if you are, a compressor is good to blow out water.
And its really easy to overheat and burn the flux in a joint too.
And if you choose to hire someone to ProPress the repair and it leaks.. propressed fittings can be brazed. I've done it to make sure it works.