not much slack in those cables. I was able to get bay by just loosening the front brake cable & re-tightening afterward but the other cables had enough slack. depends on how much you raise the bars & how slack you have to play with at the derailers & calipers. other than those extensions are really easy to attach. I've done it on two bikes. a bike shop can do it for you if you get started & feel uncomfortable finishing

here's one of them (which had many other changes)

stock photo (before)

after



here's my other (current)

stock photo (before)



after