The current Thread-less stems couldnt be simpler to change ,, the bars com out wit a face plate that is removable

and once you remove the top cap bolt on the stem the 2 bolts on the side release their grip on the steerer tube,


But those 2 last steps also loosen the headset bearing preload adjustment. which you then must re do

by replacing the stem and putting the bar back on . and tightening the face plate bolts .

and replacing the top cap bolt .. that is your headset bearing preload adjustment ,

then tightening the bolts that grip the fork steerer maintain that adjustment .


sight unseen I really cannot suggest what you should get .. a really short extension is one option, an up angled one is another .

and I really dont know what kind of bike you have if curved down drop bars , yes the swap is a rather extensive project.