Updates to release instructions

RELEASE.md

@@ -14,6 +14,21 @@ We publish the npm packages, a Python source package, and a Python universal bin
 See the Python docs on [package uploading](https://packaging.python.org/guides/tool-recommendations/)
 for twine setup instructions and for why twine is the recommended method.
 
+## Getting a clean environment
+
+```bash
+cd release
+conda remove --all -y -n jlabrelease
+rm -rf jupyterlab
+
+conda create -c conda-forge -y -n jlabrelease notebook nodejs twine
+conda activate jlabrelease
+git clone git@github.com:jupyterlab/jupyterlab.git
+cd jupyterlab
+pip install -ve .
+```
+
+
 ### Publish the npm packages
 
 The command below ensures the latest dependencies and built files,
@@ -83,6 +98,27 @@ xckd repo
 
 ### Updating the xkcd tutorial
 
+- Clone the repo if you don't have it
+
+```bash
+git clone git@github.com:jupyterlab/jupyterlab_xkcd.git
+```
+
+If the updates are simple, it may be enough to check out a new branch based on
+the current base branch, then rebase from the root commit, editing the root
+commit and other commits that involve installing packages to update to the new
+versions:
+
+```bash
+git checkout -b 0.xx # whatever the new version is
+git rebase -i --root
+```
+
+"Edit" the commits that involve installing packages, so you can update the
+package.json. Then skip down to the step below about creating tags. If the edits
+are more substantial than just updating package versions, then do the next steps
+instead.
+
 - Create a new empty branch in the xkcd repo.
 
 ```bash
@@ -106,6 +142,8 @@ file from the previous branch, as well as the `package.json` fields up to
 `license`.
 - Push the branch and set it as the default branch for the tutorial repo.
 - Submit the PR to JupyterLab
+- Publish the new @jupyterlab/xkcd npm package. Make sure to update the version
+  number in the last commit of the branch.
 
 If you make a mistake and need to start over, clear the tags using the
 following pattern: