After installing the new version, check for an update option from the dropdown menu in the upper-right hand corner of the forum extension page in the extension manager. To get ther, click on the Ext Manager button in the tools section of the backend menu. Select "Loaded Extensions" from the dropdown menu. Click on "CHC Forum." You'll see the menu in the upper right hand corner (assuming the chc_forum extension is, in fact, installed). Select the update option from that menu. If the option doesn't appear, it means you either don't need to update or that you already have updated your data.

In previous versions of the forum, conference r/w access was stored in a single field called "auth_forumgroup_rw". In this and subsequent versions, this data is stored in two fields: auth_forumgroup_r and auth_forumgroup_w. The update script simply takes the value from the old field, copies it into the two new fields, and deletes the value in the old field.