Tractor Repair: replace valve guides in farmall tractor, valve, guide

Question
i would like to know how to replace my valve guides on my farmall model H tractor. do they go in from the bottom or go down thru from the top. thinks . c. jones

Answer
never worked on this tractor but any valve guides I've seen are from the top down and have a collor to stop them from working their way down but not all heads have replaceable guides to be honest i normally would leave an engineering firm who repair heads do any of this type of work as the guides might need to be reamed after fitting them but I'm sure if you phone your closest engine remanufacturing firm and they will let you know if you can do this yourself