Generally, we recommend moving past members to the Former Members list rather than removing them, as this retains their role history in case they ever decide to re-join the club.
In any case, just click in the row for the member (which checks the checkbox at left), then select Move to Former Members (or Delete) from the drop-down.
This is explained in our online docs:
support.toastmastersclubs.org/doc/item/m...hip-management-index
Please get familiar with our online documentation.