You can remove a reference to destination cluster using the REST API. A destination cluster is a cluster to which you replicate data. After you remove it, it will no longer be available for replication via XDCR:

shell> curl -v -X DELETE -u Administrator:password1 10.4.2.4:8091/pools/default/remoteClusters/remote1

This will send a request similar to the following example:

DELETE /pools/default/remoteClusters/remote1 HTTP/1.1
Authorization: Basic QWRtaW5pc3RyYXRvcjpwYXNzd29yZDE=
User-Agent: curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5
Host: 10.4.2.4:8091
Accept: */*

If successful, Couchbase Server will respond with a 200 response as well as the string, 'OK':

HTTP/1.1 200 OK
Server: Couchbase Server 2.0.0-1941-rel-community
Pragma: no-cache

....

"ok"

For more information about XDCR and references to destination clusters via the Couchbase Web Console, see Section 5.8.5, “Configuring Replication”.