Threadless stems are super easy to replace since they have open face plates and slip off the steerer tube,

once you remove the top cap ..

re install the top cap and then readjust the bearing preload, then tighten the stem around the fork.

Extensions and up angles are some of the many variants of stem shapes ..

It is possible to just replace the fork Since its a common Surly , and have the whole steerer to use

should its cut length seems too low.. .. spacers above and below the stem are fine..