If you can, spin up another datastore and connect all your hosts to it. then do a Storage VMotion of all your good VM's onto the new datastore.
Once your old datastore is evacuated, turn it off from your SAN device. Go into your SAN device and kill any connections you see to that old LUN.
Once you verify all connections are gone, re-present the LUN to another ESXi host that is not part of your cluster, then delete the lck folders and .lck files. Once it's cleaned out, reconnect your ESX hosts in your cluster and do a storage vmotion back onto that datastore.
Next do whatever cleanup you need to do.