Minolta: how to adjust XL-401/601 meter
It is easy to open these cameras and adjust the auto exposure system. You might want to calibrate the light meter in order to use the new color film E64T. The camera will think this film is rated 40ASA so will over-expose by 2/3 stop.
You simply remove three screws to remove the body panel. Longest screw is at the top:
The small variable resistor is circled in the picture below. Move the arm very slightly clockwise in order to reduce the exposure. You can mount the camera securely and have a constant light source, this makes it easy to see the aperture setting on the camera while you make the adjustment. You may want to mark the original position of the potentiometer in case you need to return it to the original setting.
When you put the cover back on make sure the macro switch is in the correct position.
Some suggest that this procedure is the same for the Minolta XL-400.
A more precise and technically correct form of modification is explained in this document (in French): https://www.cine-super8.net/pub/tzips/minolta_etalonnage_cellule.pdf