CONTRIBUTING updated

CONTRIBUTING.md

@@ -4,10 +4,12 @@ Welcome to the Eclipse AASX Package Explorer repository.
 
 Whether you're new to the project or joining from the previous repository at admin-shell-io, please see the [Joining Development](#joining-development) section below to get started in the new repository.
 
-The [Contribution guildelines](#contribution-guidelines) section includes general guidelines as well as additional quirks specific to Eclipse Foundation projects, so it is definitely worth a read as well.
+The [Development guildelines](#development-guidelines) section includes general guidelines as well as additional quirks specific to Eclipse Foundation projects, so it is definitely worth a read as well.
 
 ## Joining Development
 
+### Eclipse Foundation incubated project
+
 AASX Package Explorer is an Eclipse Foundation incubated project and therefore needs to adhere to Eclipse Foundation rules.
 This introduces a slight overhead for every contributor, at least at the very beginning, but it's worth it!
 
@@ -17,7 +19,7 @@ Follow these steps to become a Contributor in Eclipse AASX Package Explorer (and
 1. Log in to your Eclipse account and digitally sign the [Eclipse Contributor Agreement](https://www.eclipse.org/projects/handbook/#contributing-eca);
 1. Make sure to add your github name (`Edit my account` > `Social Media Links` > `GitHub Username`)
 1. Clone or fork the repository and create an initial commit
-    - if you have preexisting work that you'd like to include, see TBD
+    - if you have preexisting work that you'd like to include, see [Migrating Development](#migrating-development)
     - ensure that the author credentials on the commit record match the email address and/or GitHub username associated with the Eclipse Foundation Account
 1. Create a pull request and work with the project team to merge the contribution
     - your request will need to be reviewed and approved by an Eclipse Contributor (GitHub Maintainer role) 
@@ -26,7 +28,54 @@ Follow these steps to become a Contributor in Eclipse AASX Package Explorer (and
 
 For more details see ["Contributing" in Eclipse Foundation Handbook](https://www.eclipse.org/projects/handbook/#contributing-contributors).
 
-## General development guidelines
+### Migrating development
+
+If you are moving over from admin-shell-io, you can simply clone the repository anew and work on a clean slate. 
+
+However, if you have local changes that you want to take over, you will need to update the remotes with the new repository url.
+
+Here is how to  
+switch from `https://github.com/admin-shell-io/aasx-package-explorer`  
+to `https://github.com/eclipse-aaspe/aaspe`  
+from the command line:
+
+1. First, we suggest to `fetch`/`pull` and `commit` all local changes.
+
+2. We can check the current remote anytime with `git remote`:
+
+```
+D:\aasx-package-explorer> git remote -vvv
+origin  https://github.com/admin-shell-io/aasx-package-explorer (fetch)
+origin  https://github.com/admin-shell-io/aasx-package-explorer (push)
+```
+
+2. Remove the old remote called "origin" with `git remote rm <remote-name>`
+
+```
+D:\aasx-package-explorer> git remote rm origin
+```
+
+3. Add the new repository url as a remote, also called "origin", with `git remote add <new-remote-name> <new-remote-url>`
+
+```
+D:\aasx-package-explorer> git remote add origin https://github.com/eclipse-aaspe/aaspe
+D:\aasx-package-explorer> git remote -vvv
+origin  https://github.com/eclipse-aaspe/aaspe (fetch)
+origin  https://github.com/eclipse-aaspe/aaspe (push)
+```
+
+4. The git links have been successfully updated. Now you can push a local branch with your work to the new repository using `git push -u <remote-name> <new-remote-branch-name>`
+
+```
+D:\aasx-package-explorer> git push -u origin mf/branch
+```
+
+> [!note]
+> Please note, it would also work to leave the "origin" untouched and just create a second remote, for example called "aaspe".
+> In this case, you need to specify which remote you want to pull from/push to.
+> It is easier to stick to the usual default remote name "origin".
+
+## Development guidelines
 
 tbd:
 
@@ -35,6 +84,9 @@ tbd:
 - pipelining/admin/configuration
 - releases
 
+> [!tip]
+> Additional information can be found at the [devdocs](https://admin-shell-io.github.io/aasx-package-explorer/devdoc/) (work-in-progress)
+
 ### How to contribute
 
 Mechanics of how to actually contribute (e.g., merge/pull requests) are described in [AASX Project Explorer Devdoc](https://admin-shell-io.github.io/aasx-package-explorer/devdoc/getting-started/intro.html).
@@ -69,7 +121,7 @@ additionally have an Eclipse Foundation account and must have a signed Eclipse
 Contributor Agreement (ECA) on file.
 
 
-## Eclipse sources - useful links
+## Appendix: Eclipse sources - useful links
 
 ##### Development process