I used a Stannol No-clean X32-10i Flux pen. Reason for choosing this particular pen is that it was the cheapest one that said "no clean" on the label.
Using lots of flux surface tension pulls the solder under the pins. Much easier than expected. The only issue is that I can not see if the solder joints are good. To fine detail for my eyes. So I used a multimeter to double check each joint. Had two without contact and one unintended bridge. This was easy to fix.
The hardest part was aligning the pins to the board.
The other parts (resistors and caps) were just pretty small but easy to solder as well. My experience was: whenever something would not work: more flux and it works fine 
Btw: does anyone know a source for reasonable priced flux. The flux pen had a rather hefty price tag.
Udo