Edit the panel.cfg file (back it up first)

If the gps is in its own pop-up window, simply replace the [Window.xx] section with one from a default ac.

This is the gps window from the  default c172.
.............................
[Window02]   <---change ## to match the section your'e replacing.
size_mm=150,250
position=8
BACKGROUND_COLOR=16,16,16
VISIBLE=0
ident=GPS_PANEL

gauge00=gps!gps,0,0,150,250
.............................

If the gauge is included in  the main panel, edit the gps 'gaugexx=' line in the main panel [Windowxx] section, usually [Window00].

gauge00=gps!gps,0,0,150,250 <--change ## to match the line your replacing.

In this case, you'll no doubt have to edit the position and maybe the size:

=gps!gps, x pos, y pos, x size/pixels, y size/pixels.

Dave