how do i reactivate my old boostmobile phone to my current phone number. my ol

Does your old phone work with your current network? If so, do they both use SIM cards? All you really need to do is put the SIM card in whatever phone you want to use, as long as it is compatible with your service provider's network. If your phone's don't use SIM cards, you'll need to contact your service provider directly to do this.