Just write a new will or you can simply add a Codicil. No lawyer needed.
You cannot amend your will after it’s been signed and witnessed. The only way you can change a will is by making an official alteration called a codicil.
You must sign a codicil and get it witnessed in the same way as witnessing a will.
Changes of name don't invalidate anything as long as the person is still identifiable.
If you (or a beneficiary) change address then it is sensible to put a note (the codicil) in with the will, to make it easier for the executors - so if you are keeping it yourself, pop a note into the envelope with the will (don't write on, or staple anything to, the will itself) to say (for instance "Fred Jones moved from 1 Acacia Avenue, Smallville, to 17 Wayne Road, Gotham, on 4th Jan 2021" or Janice Smith changed her name to Janice Williams in 2020", as it makes it easier for your executors to trace the people when the time comes.