Changing your contact details is a common occurrence in life, though it is important you keep UKVI and the university updated with any changes, so important communication can be received by you.
To update UKVI, you must use their form which gives a list of acceptable reasons for making a change.
To update the university, you must do the following:
Go to the student portal
Click “Student Records” link at the top of the page
Click personal information
Click update “view/update address(es) and telephone number