You don't. Texas doesn't require registration.
Since the state of Texas doesn't require handgun registration, the answer is, zero.
If you are asking how to change registration of a handgun in Arizona, the answer is, you don't. There is no such thing as registration. Arizona does not require it, and there is no national registration.
Rifles and shotguns, yes. Handguns, no, you must be 21 to legally purchase a handgun.
A regular handgun, no. There is no registration in TN.
No. The state of Kentucky does not require handgun registration.
Yes, Illinois requires handgun registration.
No, Missouri does not require handgun registration.
I'm pretty sure Texas doesn't have registration, and there is no national registration, so the answer is, basically, you can't, because it isn't "registered" to your name. If you are selling a handgun and want proof you don't own it any more, sell it through a licensed dealer, or if you sell it by private sale, get the buyer to sign a bill of sale.
yes
The basic answer is, you can't.
the state of Missouri does not require handgun registration.