Yeah.
“Annything is possible.”
Remember that post? 
No, it really isn’t. Face it Spencer, you are wrong. Just deal with it.
Yeah it is!
Anything is possible! It can happen, but like Pheenix said, it would require serious modding.
It’s not even called modding when you have to remake titanium. You’d actually have to destroy all of those yoyos and THEN you’d be able to do it on any yoyo. But you’d have to actually make a new yoyo to fit it, and then you are still stuck since you’ve failed on the ones you couldn’t fit.
It doesn’t have to be titanium.
Well if you are saying you could do that, then you could also drive a car into a light pole at 80 miles an hour and still drive it. Sure, you would have to seriously fix/mod it but you still could. Of course it would just be easier to get a new car.
Yes, but it depends, which car, and did you do anything to upgrade it before?
My story
I was bored in the car and had two yo-yos; Cream and Hectic. I just unscrewed and rescrewed them in my boredom. Soon, I got curious and put the Axle half of my Cream into the non-axle half of my Hectic.I unscrewed and what do ya know, the Hectic took the Cream’s axle.
I couldn’t get it about for about a day or two.
Same with my BKs, but now it is just half green half black.
That would look cool. 
Actually, I’m not sure why but at one point I had two L3’s and they had very different axle sizes. Not sure why but my guess is different runs or something.