This is most likely the trickiest part. My way is, to add some solder to the left mounting point and move the port into position while heating up this point. I then secure the other side with more solder and connect the pins at last. When soldering the data pins I add some solder to them and then move the solder iron from the port away until there are no short circuits. (Except the one between the two connections next to VIN, those are required by some cheap power supplies to detect that a device is plugged in.)
I recommend folding the legs before soldering them. This makes soldering way easier.
M0 is for programming the ESP, M1 is for stability when connecting adapter PCBs and therefore optional.
Step one is, to connect the 3V3 jumper on the backside and verify that the converter outputs 3V3,´. If it is not, you may need t adjust the potentiometer on the front side using a screwdriver. I also got my converter with some pin headers attached which made the soldering very easy. But this step is not required and you can also lay the converter onto the PCB and add a lot of solder to it. This step may require some creativity.
10nF capacitor to C1
100uf capacitor to C2
I am using 2x (1x4) pin headers. To solder them more easaly I plugged in an dead ESP to hold them together. But be carefull and fast! To much heat may damage something.
Bend the legs of the MOSFETs so they fit into the lines marked on the PCB
I don't know 100% if they are really necessary but they may help discharge the MOSFET gate and prevent them from breaking. I am currently monitoring this. For now you should be save to skip this step.