First of all you need to have more than one IP in your hosting plan in order to change the IP or a domain / cpanel. you can do this either when creating the cpanel account or after.
Changing IP when Creating a Cpanel Account.
when you create cpanel account from WHM panel through ‘Account Functions‘ –> ‘Create a New Account‘ , enable ‘Select Options Manually’ to view dedicated IP option.
after enabling manual options, you will be able to select an IP from the settings section.
select which IP you need to assign for this cpanel account from the above ‘Select the IP Address‘ drop down menu. you can only assign a dedicated IP for one cpanel account.
Change the IP after…
for changing the IP for already created cpanel account, go to Account Functions –> Change Site’s IP Address and select which account / domain which you need the IP changed. then click ‘Change‘
from the drop down menu, select an available IP and then click Change.
You will experience some downtime after changing an IP from few minutes to 72hrs max.