The member can do it from their profile page, or as keymaster you can log in and edit their profile for them. As keymaster just click on the user’s title (normally “Member”) and in their profile there is an “Edit” tab or button. That will allow the keymaster to edit a member’s profile. A user can click on their own name at the top of the page and be brought to that same profile page, and there is an edit tab there for them as well (I think it’s the middle of three tabs, on the top right.) Post back if that resolves the problem for you.
Sorry, didn’t make myself clear. When someone registers they need to fill in a load of details, but what if you want to add extra stuff there. Company name, or Type of Motorbike or anything else. Is there a way to actually alter the fields in the registration document?
Ahh. You want to extend the registration form then.
This plugins do something similar, maybe you could use one as a starting point?
https://bbpress.org/plugins/topic/bbsocialize/
https://bbpress.org/plugins/topic/gaming-codes/
https://bbpress.org/forums/topic/plugin-allow-additional-or-custom-profile-fields
Also, there has been some discussion recently in these forums of just how to do this, but I can’t find it right now.