Visual Studio Team Services - edit link settings

For anyone coming to this answer later, I'm using Azure DevOps Server 2019, and the names of things have changed. I can get to the definition of "Solution" by going to Task -> Pipeline -> Parameters.

When you link a setting from a build task it will not be editable in the Task itself. To edit it you need to go to the Process section of your build definition. There you can see a new parameter is added that maps to the solution setting in your MSBuild task.

You can see in the above image, the new parameter that was added to the process section of the build definition. You can clearly see if you unlink the setting from the build definition, the parameter will be removed. Here if you want, you can select the full path to the solution instead of using a wildcard