Mercurial - backout an old merge

Question

I have a branch that looks like this:

A->B->C->D->...->Z
     ^
1->2-^

where C is a merge from 2 an

Answer 1

You could use the thg backout tool.

1. Update to the merge change set (C)
2. thg backout
3. Pick which parent you want to backout (whatever the revision for (2) is) - Note you actually pick on the dialog the parent whos changes you want to keep not backout.
4. Click Next
5. Click Commit

This will create a new head which you will need to merge with Z or rebase on to Z.