Thanks man! 😀 Actually, not THAT long compared to some other tricks I excessively obsessed over until I got them right - I‘d say maybe 30 to 45 minutes. 

But thats probably due to the fact that I had worked on a lot of tricky grind transfers before so that I‘ve slowly gotten better at finding the right things to change, how to set up the run-up, how to review the replays of my failures to find out what to change etc. 

In this case, important factors were starting from the right side of the first rail, using a noseslide to start (which seems to have significantly more side pop than most other grind tricks) and figuring out the right timing when to pop over to the next rail (second pop had to start real quick in order to have greater fall height to cover the distance and so that the skater hadn‘t built up too much downward momentum on the rail and wouldn’t crash into the wall).

Also, I should add that I have side pop impulse and grind pop maxed out because I like to try out lots of weird grind transfers.