We recently updated ours for the same reasons - had made them ages ago, long before any Gdcs we wanted to include.
We just rewrote them, using much of the same wording as in the solicitor-prepared originals, but with additions and replacement executors, i.e. dds instead of siblings.
This was not long after the beginning of the first lockdown (what if we both died of the virus??)
We we lucky to have neighbours willing to act as witnesses - out of doors and socially distanced - with the wills on a folding table between us!
We have named both dds as joint and several executors, i.e they can act alone or together, as they choose. Makes it easier in practice, since both would not need to be present to sign anything. Dh has been an executor several times so well aware of PITA factors when it can be quite enough of a hassle anyway.