just go to the console and go to the folder where the vmx is stored of the vm. all the way down of the vmx there should be a "sched.swap" or something like that. Just change it to the right location. (it uses the vmfs identifier as you will notice and that is why adding a new datastore with the same name won't work!)
Available now on Amazon: vSphere 4.1 HA and DRS technical deepdive
Duncan is absolutely right. I did same someyime ago.
The line you to change is
sched.swap.derivedName = ".vswp location"
Hope this helps
I found myself in a simillar situation during the update from vSphere 4.1 to 5 and upgrade of VMFS datastores from VMFS 3 to 5.
After I've found this thread it seemed to me like a lots of work to manually adjust swapfile location for each vmx.
So I investigated in vCenter MOB and found easy way out.
You have to go through:
childEntity (pick the right DC)
childEntity (pick the right cluster)
host (pick the right host)
and there you Invoke the "UpdateLocalSwapDatastore" method with cleared parameter value.
This will reset the Local Swapfile Datastore on the particular host to default value.
Then you can set the right datastore from the GUI.