Well I got a little impatient today and decided to let my new Interrupta out 3 days ahead of schedule. I mean my existing Interrupta wasn't showing any signs of aggression to the new one in it's acclimation box. It seemed like it was ignoring it.
It wasn't a good idea. Right when I let the new one out, mine starting to chase it around my tank fervently. I was extremely worried because I had no idea to how to catch either one. Well luckily, mine laid off the new one for a bit and the new one rested near a corner. I was able to scoop it up quickly with a net and now it's back in it's acclimation box. It was breathing very heavily as with my existing Interrupta too but they've both calmed down. My existing Interrupta is now standing guard around the acclimation box.
PLAN B: I'm gonna catch my existing Interrupta with my fish trap tomorrow. Then I'm going to put it in my refugium for a good 2-3 weeks to let the new Interrupta establish itself in my tank. In that time, the existing Interrupta should un-establish itself too and forget about it's dominance in the tank. I've done this process a couple of times with domineering fairy wrasses and it's worked in the past. So hopefully it'll work this time around too.
Wish me luck guys!