Create a development profile in Firefox.

Go to your Firefox profile directory then to the "extensions" sub-directory.

Configure Git:

$ git config --global user.name "YOUR NAME"
$ git config --global user.email YOUR_EMAIL@ACME.COM

Get the latest version of LaSuli:

$ git clone ssh://YOURSOURCEFORGEACCOUNT@lasuli.git.sourceforge.net/gitroot/lasuli/lasuli/

Rename lasuli directory into lasuli@hypertopic.org.

Restart Firefox with your development profile.

Develop and test.

Whenever you get a new feature or fix:

$ git add CHANGEDFILES
$ git commit 

Publish your changes:

$ git push