is there any way to delete a specific panel on msd4?

Select the Object Selector (O on your keyboard), and select your Panel Ruler Layer.

Then, you can either click and drag along all four points/walls of the panel, or click on one wall, while holding down the Ctrl key (that will select all the points/walls).

Finally, either select Ruler -> Delete Selected Points from the main Menu, or press Ctrl+Delete on your keyboard.

Ask away!