Single Branch - Abandon multiple consecutive bad changesets and reset/restart from last good changeset

[AndyDB]

Two of us collaborate on a Unity project and checkin/out using PlasticSCM repo
Our PlasticSCM Repo has a single "Main" branch.
Due to a technical problem, we had a number of consecutive changesets (commits) which are corrupt and we want to abandon.
e.g. Our last good commit is ChangeSet 183 - ChangeSets 184->188 are corrupt and we want to abandon them.
We have "Switched workspace" to ChangeSet 183 and got our repo back to that point.
We now want to move forward from ChangeSet 183.
What is the best way, in PlasticSCM, to proceed with changes, commits etc to our repo from ChangeSet 183 while abandoning all the corrupt changes in ChangeSets 184->188? 
Any advice on this "basic" problem would be greatly appreciated.

[AndyDB]

Ok - In the Changesets tab I  right-click Switch workspace to this changeset. This got me back to the Workspace pre corrupt changesets 184-188.  Then, starting with changeset 188 I selected the changeset, right clicked and selected Advanced->Delete changeset.   I deleted changesets 188->184.    Then I made my first new changes and committed them.  Now I had new changeset 189.  My colleague synced to this changeset we are back in business.  Corruptions gone.