How do I convert my phone from the Sprint to TMobile network?

[smilinzena]

sprint to tmobile settings?

so my daughter purchased a google nexus 5 on CL today that was being used on sprint, well i pulled a sprint sim card out of it when she got home. when i stuck my tmobile prepay in it, i chose the tmobile network in settings it sent back a message "can not connect to network please try later" or "can not connect to network"

please can someone tell me what needs to be changed on the phone and how to change what ever if anything i have to change.

please note i do not speak robot, so please explain as clearly as possible.

thanks very much !!