Anyone interested in helping out with the Build WG can reach out to existing members to let us know, for example via a Github Issue on this repo or through IRC.
Membership of the Build WG involves granting infrastructure access, so full membership of the WG can be a gradual process. However we welcome anyone willing to contribute, and we're always working to make contributions easier.
Once you're an established contributor, an existing Build WG member will invite you to join the WG. A PR adding your name can be raised by either you or them (e.g. #524) and once that gains consensus and is landed you will be onboarded (see the onboarding doc for more details).
Existing members may require one of the additional accesses documented in [access.md][] by raising a PR adding their name to the relevant section of the Readme. It will be reviewed and approved by the WG like any other request.