in a well established tank one way to do this is
get 2 dividers, taller than your sand bedand section off a part of you bed, abou 1/3,
then take out the cc, and replace with sand, with acouple of days(making sure water is in line),
tehn section off another section and repeat, and so on, if you have lr this can be tricky, and obviously if you have a ugf, it needs to come out, alsoo try to keep your dust low to help alleviate stress on your fish, one thing you can do is add ls, and/or use a pipe(clean unused pvc) and pur the sand through to the bottom, these may help with dust
but by all means get it all out