Sentry has improved its Slack integration, allowing users to send specific types of errors to specific channels and assign issues to Sentry teams or users from within Slack. The new integration also enables resolving issues directly within Slack. To set up the new integration, users need to remove the old one if they are currently using it, and then add the new integration to their project settings. The process is straightforward, with a step-by-step guide available on the Sentry website for configuring Alert Rules and setting up the integration.