Hide toolbar(save,accept, reassign)

This is fundamentally different in modern versions of Appian - there's no longer one "toolbar" and no way to "hide" it wholesale.  Saving an in-progress form is controlled in one place, the ability to reassign it is controlled somewhere else (in the "assignment" tab mainly, in advanced assignment properties), and AFAIK a user will *always* have the ability to accept a group-assigned task that they have permission to see.

This is fundamentally different in modern versions of Appian - there's no longer one "toolbar" and no way to "hide" it wholesale.  Saving an in-progress form is controlled in one place, the ability to reassign it is controlled somewhere else (in the "assignment" tab mainly, in advanced assignment properties), and AFAIK a user will *always* have the ability to accept a group-assigned task that they have permission to see.

basically i want to hide the appian default reassign button because we are using site for the user and they want to reassign button 

Then as I mentioned, you will need to set reassignment priveleges to "none" in the Assignments tab of the task (and/or swim lane).