Valve stems

Do i have to remove the tire from the rim to remove the valve stem or can i just pull it out? I all ready removed the core.

You have to have a valve stem puller first, The bottom of the valve stem generally stays on the bead of the rim, so you'll have to at least break the bead of the tire down to get the valve stem completely off.

you can probably pull it out with the tire on the rim but to put in a new one you need to at least break the tire off the rim. just wondering why you want to change them? usually if they leak you can just tighten down or replace the core only

I just wanted a valve stem for my boost leak checker and i had 4 extra tires/rims so i was gonna take one off there. But i just went out and bought one