So, If you successfully remove the cap of the axle side of the zero, then remove the axle then put it to the other halve right?, So You’ll screw it, Is that thing won’t crack?, I mean it would become tighter It make cause to crack due to tightness.
Help! 
You aren’t making much sense but I’ll try to decipher.
After you get one side cap off all you need to do it put the axle into the nut of the other side and slam it the same way to get the other cap off. If you slam it it won’t crack the cap.
Or you could just leave your yoyo together and simply pry the caps off with a knife. I HAVE done this with two seperate FHZ’s and it works fine. It’s a lot easier than disasembling your yoyo.
doesnt sound the safest i would use a jewelers tip screw driver
That’s a good idea, but a jewelers tip screwdriver is harder to find lying around the house than a knife for most people. If you do use a knife, try to use the smallest one available.
Those methods will also cause you to mark up your yoyo. Imagine if you slip and scratch the crap out of your cap? I don’t suggest this way.