How about doing it as a post load script like this (tested on my local package-cache)...
oldPackageName := 'ShoutTests'.
newPackageName := 'Shout-Tests'.
repository := MCRepository allSubInstances detect: [ :repo | repo location =��
'/Users/ben/Library/Application Support/Pharo/package-cache' ].
oldPackage := RPackageOrganizer default packageNamed: oldPackageName.
newPackage := oldPackage renameTo: newPackageName.
mcWorkingCopy := newPackage mcPackage workingCopy.
uniqueNewVersion := (mcWorkingCopy uniqueVersionNameIn: repository) trimBoth.
newVersion := mcWorkingCopy��
newVersionWithName: uniqueNewVersion��
message: 'Issue 14439 - ShoutTests should be Shout-Tests'
in: repository.
newVersion ifNotNil: [
Cursor wait showWhile: [
[ repository storeVersion: newVersion.
] ensure: [ (MCVersionInspector new version: newVersion) show ]
]
].
For reference, I munged that together from tracing NautliusMonticello>>commit:in:��