Start Eclipse, then select Help > Install New
Software.
Click Add, in the top-right corner.
In the Add Repository dialog that appears, enter "Gitlab Mylyn Plugin" for the Name and the
following URL for the Location:
https://pweingardt.github.com/mylyn-gitlab
Click OK. If you have trouble acquiring the plugin, try using "http" in the Location URL,
instead of "https" (https is preferred for security reasons).
In the Available Software dialog, select the checkbox next to the Mylyn Gitlab Connector and click
Next.
In the next window, you'll see a list of the tools to be downloaded. Click
Next.
Read and accept the license agreements, then click Finish.
If you get a security warning saying that the authenticity or validity of
the software can't be established, click OK.