Update the version in cap32.h:
$ vi src/cap32.h
(...)
#define VERSION_STRING "vX.Y.0"
(...)
And commit the change:
$ git commit -m "Create version vX.Y.0"
Tag the release:
$ git tag vX.Y.0
Push the result:
$ git push
Delete the latest release from github, it will be recreated by the next push. It's probably a good idea to immediately trigger a build by pushing a dummy change.
Create a branch from the existing tag and switch to it:
$ git checkout -b vX.Y vX.Y.0
Do the required modifications and then tag it. Push the result:
$ git tag vX.Y.0
$ git push
Verify that appveyor releases it properly.
Delete the latest release from github, it will be recreated by the next push. It's probably a good idea to immediately trigger a build by pushing a dummy change.