It depends on the make & model of your bike. On my Pedego, it's fairly easy. The wire wrap needs to be removed until the connector is accessible. Then it's just a matter of unplugging the old display, removing it from the handlebar and connecting & remounting the new one.
My humor was based on the total lack of information about the ebike. Are you replacing it with a factory part, looking at generic Chinese display, what bike and display is it?, etc...... Some companies have a proprietary protocol language between the controller and the display, so you can't mix and match.
I get it. Not yet and hopefully not ever. The problem is some time on the display there appears to be a burn mark in the upper left corner. I'm wondering, could this be the beginning of a display on its way out?, and if so how difficult would it be to replace. The bike is Aventon Pace 500.