The valve guide remover is used with the spring removed, but (by necessity since it is "captive") the valve is in place - but lifted "up" as high as it will go.
THEN the valve guide remover is placed "around" the valve stem with the small part down and the valve "backside" seats onto the larger top of the guide remover.
The valve and remover are then lowered until the remover "touches" the top of the valve guide - and the top of the valve is "tapped" with a hammer. Not too hard lest you damage the valve. The guide is pushed down into the valve spring chamber.
The valve guide remover is reproduced and they're quite functional even in the repops.
Joe K