I presume you are using a Vegas edit program, which version and buildnr.? You have to duplicate the (part of) track and cut off what you don't want from the upper track with Pan/Crop and than with Motion Track put it over your trash, look
I presume you are using a Vegas edit program, which version and buildnr.? You have to duplicate the (part of) track and cut off what you don't want from the upper track with Pan/Crop and than with Motion Track put it over your trash, look
But if you also state here your version and buildnr. maybe you can get other help that does it faster, f.i. with the PIP FX that was included from version 15.