I'm using GIS to map the movement of animals and their speed and density in different habitat types using shape polygons.

When I got to the step ;Count points in polygon' a pop up window appeared saying:"CRS warning! Warning: Input layers have non-matching CRS. This may cause unexpected results.” I clicked ‘ok' however this meant that the attributes table that I then opened had no GPS speed values.

I'd like to know how to convert the CRS for this habitat shape polygon from 'Selected CRS (EPSG: 4326, WGS 84)' to 'Selected CRS (EPSG: 7405, OSGB 1936 / British National Grid)'.

If you could help I'd be immensely grateful, thank you!